Introduction: Joint strength of the lower limbs plays a decisive role in the competitive ability of long jumpers. Special strength training based on science and targeted at the strength of the lower limb joints is an essential topic for long jumpers. Objective: To analyze isokinetic muscle strength characteristics of lower limb joints in long jumpers. Methods: Voluntary jumpers were submitted to isokinetic concentric contraction tests of the lower limbs and hip joints. We also analyzed the effect of strength training on lower limb joint injury. Results: The knee muscles of the athletes have reduced eccentric contractility. The ankle of the athlete has the most vulnerable joint to injuries in the sport. Conclusion: The explosive force and eccentric contractility of long jumpers’ lower limb extensor muscles have the most significant impact on joint thrust and extension speed. Athletes need muscle strength training to develop isokinetic muscle strength. This can effectively prevent injury to lower extremity joint movements. The research findings of this paper can provide a specific theoretical basis for formulating scientific training for long jumpers. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.