Abstract: The slow response characteristics of output current signal of vanadium self powered neutron detector (VSPND) seriously affect the real-time response of the neutron flux measurement in the reactor, which is not conducive to real-time control and safety management of reactor. Inverse function calculations or various compensation methods are used to improve the response characteristics of VSPND, which is beneficial to the use of it. The forward difference transform method, backward difference transform method, step response method and bilinear transform method of digital processing algorithms were studied, and post-processes method was proposed. The response time of output signal of VSPND is shortened effectively. The time constant is reduced from 325.47 s to less than 7 s, and the time constant of step response method is the smallest, which is 5.2 s. A digital experimental system was designed, which verifies the correctness of the algorithm. It provides the feasibility for the rapid response of VSPND to measure the neutron flux in the reactor.