The occurrence of knee joint sports injuries in wushu sparring training can bring great harm to athletes’ lives as well as their work. For this reason, this paper proposes a monitoring and prediction model for knee joint injuries in martial arts sparring. We synthesize the causes and components of sports injuries by conducting a theoretical analysis of the fundamental circumstances of knee joint injuries. We construct the sports mechanics model by combining the kinesiology and physiological structure of the knee joint. Next, we gathered the knee joint forcefulness parameter data using a sensor and a mechanical model, preprocessed the data, and built a sports injury monitoring model for the knee joint using WNN, verifying its effectiveness. The multiple regression equation of peak knee force is 35.529*speed+49.995*BMI index+81.886*gender. Moreover, the threshold of knee joint abnormality in the WNN model should be corrected to 0.563, and the threshold of meniscus tear should be corrected to 0.379. Meanwhile, with the assistance of this method and the combination of scientific preventive measures, the probability of sports injuries can be effectively reduced and, at the same time, guarantee the better development of martial arts sparring training.