In order to improve the accuracy of foot plantar pressure acquisition and reduce the influence on the experimenter’s natural gait during the measurement, the improved design of plantar pressure acquisition system and the optimization of sampling timing are proposed, which can effectively reduce the noise interference introduced by the sensor and the circuit system, and finally realize the sampling measurement of large size (71.9 cm × 33.5 cm) and high spatial resolution (2.8/cm², a total of 6720 sensor units) plantar pressure sensing system with the sampling rate of 100 SPS. The system is used to test in the Department of Rehabilitation in Guangzhou First People’s Hospital. The collection and analysis of foot plantar pressure can be applied to the postoperative gait rehabilitation training, providing effective quantitative data reference for doctors to evaluate the rehabilitation of patients and formulate targeted treatment plans.