The problem of abnormal reset of CPU board in on-orbit flight test based on TSC695F processor was studied. By using the logic analyzer to capture process data and locate the problem location, found that the root cause of the on-board computer reset is the data loading error. Combined with the chip drive capability limit parameter analysis, it was found that the actual driving load of the CPU board is an important factor determining whether the TSC695F processor reset. Once the load exceeded the upper limit of the chip driving capability, the data loading error would easily occur, which could result in a reset. Finally, the correctness of theoretical analysis was verified by simulation and experiment, and an improved scheme was proposed.