Abstract: Objective: To construct a quantitative diagnosis and precise intervention model for jump serve, namely "serve efficacy diagnosis–serve speed measurement and analysis–technical diagnosis and optimization", to provide a standardized framework for the scientific training of jump serve in Chinese male volleyball teams. Methods: Serving technical effects (3 841 serves) from the top three teams of 2022-2023 Chinese Men's Volleyball League were statistically analyzed, with 13 elite athletes of the Shanghai Men's Volleyball Team as intervention participants. Data Volley 4 was adopted to collect technical performance statistics. Serve velocity was measured using a radar speed gun, and kinematic data of power jump serves were analyzed through 3D motion capture or video feedback. An 8-week intervention training was carried out to develop a quantitative diagnosis-intervention model and to verify its efficacy. Results: The Shanghai Men's Volleyball Team demonstrated a certain advantage with a jump serve usage rate of 63.21%, but its scoring rate (7.30%) and the proportion of high-speed serves above 100 km/h lagged behind those of the Beijing Men's Volleyball Team. Unreasonable approach stride length and insufficient jump distance were identified as critical factors restricting the improvement of serve speed. After the intervention, the average serving speed of the 13 athletes increased from 97.15 km/h to 104.38 km/h, representing an improvement of 7.44%. The paired t-test revealed an extremely significant difference (t=6.20, P<0.01), with a large effect size (Cohen's d=1.72). Conclusion: The established closed-loop diagnosis-intervention model of "serve efficacy diagnosis – serve speed measurement and analysis – technical diagnosis and optimization" enables quantitative and visualized diagnosis as well as precise intervention of jump serve technique, and exerts a positive effect on enhancing the aggressiveness of athletes' jump serve.