The detection of wide energy spectrum neutrons is important in nuclear data measurement and nuclear physics. Diamond detectors play a significant role in experiments based on wide energy spectrum neutron beams due to the excellent radiation resistance and electrical properties. In usage, the polarization effect and pumping effect of diamond detectors can significantly influence the stability of the diamond detector. For the first time, we conducted a comprehensive characterization of the performance of a diamond detector under wide energy spectrum neutrons irradiation by extracting and analyzing key parameters including Pulsewidth, Peakmax, Qcal, and count rate. This work provides a technical procedure for assessing the stability of diamond detectors in complex radiation fields. Signals of different time-of-flight (ToF) can be selected based on the experimental objective, allowing for the observation of the stability of parameters of interest, such as Qcal and count.