The application of biomechanical methods and techniques in rehabilitation treatment has been explored to deepen understanding of the health recovery of injured athletes, thereby improving their efficacy and quality. There are various methods for using biomechanics, which can help people understand the patient’s movement characteristics and mechanical changes, evaluate the patient’s recovery progress, and optimize the plan. Therefore, this article mainly conducted research and analysis on the application of biomechanics in sports rehabilitation, and explained the specific role of biomechanics in it by comparing before and after sports rehabilitation in different situations. The results showed that after treatment with biomechanical methods, the patient’s muscle strength increased by 9.4%–20.93% compared to the original, and the power value increased by 0.8–4.56 watts. The effect was good for achieving 71.28% muscle activity, and there was also a significant improvement in its sports mechanics indicators. After receiving biomechanical treatment, the quality of motor skills in patients was over 60%, which showed significant improvement compared to before treatment. Therefore, when conducting sports rehabilitation, biomechanical treatment plans should be used to achieve better therapeutic effects.