Enthusiasm for sports competitions is consistently high. In sports competitions, athletes not only need to have superb skills but also need a strong psychological quality. Usually, athletes with high psychological quality can make their technical level outstanding; on the contrary, for athletes with low psychological quality, even if the level of competition is very high, it is difficult to achieve excellent results. This study analyzes the data of basketball players to study the influence of the stability of different players’ psychological quality on the performance of basketball games. The “mental state” of basketball players is negatively correlated with their performance in basketball games, and the players’ psychology often shows signs of tension during basketball games. This tension is the result of a variety of psychological effects, and the number of times of tension is different under different psychological quality stabilities. The experimental analysis results of this study show that through the data analysis of the psychological factors affecting basketball players, the key factors affecting their psychology have been explored, and strategies and methods that can effectively cultivate the psychological quality of basketball players have been found, in order to provide a reference for improving the psychological quality of basketball players.