With the progress in oilfield development, low-quality resources are gradually developed, and related research is focused on condensate gas reservoirs. Complex physical properties of condensate gas reservoirs and complex components of condensate gas system make well testing and productivity analysis of condensate gas reservoir difficult, which is the main reason why there has been no breakthrough in well test studies of condensate gas reservoirs for many years. In this study, based on the actual production data of the condensate gas reservoir of the Yingtai Fault Depression, we analyze the fluid phase characteristics and distribution law of the gas reservoir. Through the investigation of the preferred well test model, the well test interpretation analysis is carried out for the typical well. According to the system well test data, a one-point formula is established to predict the production capacity, and the production dynamics of the condensate gas reservoir is analyzed. This study can provide a theoretical basis for optimizing development of condensate gas reservoirs.