The utility model discloses a reactive compensation load device for pole-mounted transformer detection. The system comprises a load cabinet arranged adjacent to a main control cabinet, and an active branch, a 5kVA common compensation branch, three 10kVA common compensation branches, three 20kVA common compensation branches, a 5kVA branch compensation branch, a 10kVA branch compensation branch anda 20kVA branch compensation branch which are connected in parallel are arranged in the load cabinet. The device is suitable for a transformer low-voltage side load loop with the rated capacity of 400/200 kVA and the rated voltage of 10 kV/400 V. The load power factor adjustability of the device is utilized to adjust the line power factor, and the switching response time and accuracy of the pole-mounted transformer capacitor bank are detected.