To investigate the fretting wear of the contact parts of electrical connectors caused by random vibrations during operation, resulting in decreased contact performance due to wear debris, stepped stress and constant stress random vibration tests were conducted. Electrical capacitance tomography technology was used to detect the wear debris between the contact parts of the electrical connectors during fretting wear. The effects of vibration period, direction, magnitude, and load current on wear debris accumulation and distribution were studied. Surface morphology and energy spectrum analysis were conducted on the specimens after testing, and fractal dimension was used to study the uniformity of debris distribution, quantifying the extent of wear on the contact surfaces. Results of the tests show that vibration period, direction, and magnitude have a positive cumulative effect on the generation and accumulation of wear debris between contact parts. The coupling effect of load current, leading to heating and stress relaxation, delays the performance degradation process. Axial vibration causes the most severe wear, with the root of the pin being the area of severe wear. The degradation patterns of the electrical connectors under stepped stress random vibration are similar to those under constant stress, with wear debris characteristic values under stepped stress showing a certain step-change feature. Significant changes occur in contact surface morphology during fretting wear of the connectors. The results of surface morphology and spectrum analysis align with the characteristics of wear debris and the variation in contact resistance.