The purpose of this study is to explore the influence of geometric parameters of facade opening on the natural ventilation performance of large space buildings in cold regions. The National Fitness Center was selected as the research object, and the relationship between the geometric parameters of the facade opening and the natural ventilation performance was simulated and analyzed combining the parametric modeling technology, CFD numerical simulation technology and parameter correlation analysis method. Based on the field investigations of 15 national fitness centers in the cold regions, the typical space model was summarized. Four geometric parameters including the number of facade openings(Pn), the width of opening(Pw), the distance from opening to the floor(Pd) and the height of opening(Ph) were extracted as simulation variables, and the range of each geometric parameter was determined based on the survey data. The parametric model was established by setting the coupling and constraint relationships between geometric parameters. Based on the consideration of three aspects of air quality, thermal comfort and sports requirements, the air age, temperature and wind speed of the reference surface were extracted as the evaluation indicators of natural ventilation performance. Fluent in ANSYS 17.0 was used for CFD simulation analysis. Natural ventilation under the action of wind pressure and buoyancy was adopted in the simulation. The incompressible ideal gas model was used to simulate the process of natural convection. The average wind speed of the transitional season in Shenyang, a typical city in the cold region, was selected as the inlet boundary of the calculation domain, and the thermal environment boundary conditions were set in combination with the measured data. First, four groups of single variable simulation experiments were performed. With other parameters kept at their initial values, a single geometric parameter’s influence on natural ventilation performance was tested separately. According to the CFD simulation results, cloud maps of the air age, temperature and wind speed of the reference surface were extracted, and the fitting curve of the influence trend of geometric parameters on natural ventilation were drawn. The simulation results of the single variable experiments showed that the air age changed in a power function or a quadratic term with the increase of geometric parameters, and kept a negative correlation with Pn, Pw, Ph, and a positive correlation with Pd. The temperature changed linearly with the increase of geometric parameters, and kept a negative correlation with Pn, Pw, Ph, and a positive correlation with Pd. Wind speed changes linearly or quadratically with the increase of geometric parameters, and kept a positive correlation with Pn, Pw, Ph and a negative correlation with Pd. The evaluation index values of the reference surfaces of first and second floor were basically consistent with the overall average. In other words, increase of Pn, Pw, and Ph will cause increasing trend in wind speed and decreasing trend of air age and temperature; in contrast, increase of Pd will cause a slight decrease in wind speed and a slow increase in air age and temperature. Then the correlation coefficient was calculated to explore the sensitivity of each parameter. The Latin hypercube sampling method was used to obtain 200 groups of geometric parameter data. CFD numerical simulation was carried out to calculate the air age, temperature and wind speed of 200 groups of samples. Then the Spearman method was used to calculate the correlation coefficient of each parameter. The results of correlation analysis showed that the geometric parameters of the facade opening kept different sensitivity on natural ventilation performance. The comprehensive ranking of the correlation coefficient of geometric parameters in descending order was: the width of opening(Pw), the height of opening(Ph), the number of facade openings(Pn), the distance from opening to the floor(Pd). Among all parameters, Pw is the most sensitive parameter, and Pd is the non-sensitive parameter. The correlation coefficients of Pw, Ph, and Pn were close, and they were key geometric parameters that need to be considered in the design. The research results can assist architects to quickly identify key geometric parameters during the design process, and make targeted adjustments to the facade opening shape to improve natural ventilation performance. Based on the evaluation of three goals of air quality, thermal comfort, and sports requirements, the ideal wind environment for the sports space of the National Fitness Center should keep a smaller air age, lower temperature and lower wind speed. From the simulation experiments, it can be known that the increase of single geometric parameter will lead to contradictory results of the three goals. Therefore, the optimal combination of opening parameters should be the result of comprehensively weighing the three goals. In addition, this research is an exploration mainly on natural ventilation performance. In actual projects, the determination of the facade opening shape should also be combined with other design factors such as building image, daylighting and thermal performance.