Combining with the characteristics of equestrian sports and the psycho diagnosis technology and using the tools such as Visual Basic, Photoshop, Microsoft Access, Psychodiagnosis Testing System for Equestrianism Players was developed. About 40 athletes who participated in the whole national equestrian championship game and the whole nation outstanding equestrian players game were divided three terms and measured successively. Results indicate that the testing system has higher reliability and validity than traditional mental test such as good effect, simple operation convenient inquiry and objective evaluation. It can rapidly diagnose and reflect psychological characteristics and mental state of equestrian players.