<p>The displacement of the knee ligaments is an important index in the automotive safety evaluation standards. Normal draw-wire displacement sensor cannot be mounted on the knee with narrow space. This paper develops a high-performance draw-wire displacement sensor with suitable structure size for measuring the displacement of the knee ligaments of legform impactor. Its structure size is reduced and shock resistance is improved by integrating the take-up module and the signal generation module. The tiny flat spiral spring for quasi-stable tension and resilience is designed, and the special resistive paste for making high precision printing film is modulated through accuracy calculation. After sampling calibration, the fundamental error, nonlinearity error, return error, and repeatability error are 0.208 %, 0.185 %, 0.023 %, and 0.034 %, respectively. By comparing the performance index of foreign products, our self-developed draw-wire displacement sensor can replace them to fully meet the requirements of actual use. After 12000 times of fatigue test and 400 times of impact test, it can still work normally and its performance indicators still meet the needs of use. Thus, it can be concluded that the self-developed draw-wire displacement sensor has high measurement accuracy, long service life, and excellent shock resistance.</p>