Nuclear power plant xenon oscillation test data fitting method and device

The invention belongs to the technical field of nuclear power, and particularly relates to a nuclear power plant xenon oscillation test data fitting method and device. The method comprises the following steps: searching a peak value or a valley value for a time-varying curve of AO (t), and determining an oscillation period T through a time difference of a peak value of one period or a peak-valley value of a half period; any time t is selected, when AO (t)-AO (t + T/2) = 0, the corresponding time t1 =-T/4 or t2 = T/4 is obtained, AO (t) corresponding to t1 and t2 is determined as the oscillation center C, the midpoint time between t1 and t2 is determined as the point of t0 = 0, then the parameters of the free oscillation function can be determined, and therefore the reliable xenon oscillation test data processing method is provided. Therefore, correct parameters such as oscillation period, amplitude, stability index and oscillation center can be obtained, and whether the reactor core meets design requirements