The invention provides a comprehensive test device for the general test of a transformer. In one device, comprehensive devices, respectively designed for direct-current resistance test, variable-ratiogroup test, short-circuit impedance test and on-load tap switch test, are integrated together. A direct-current resistance testing module is used for sampling the current of a constant-current sourceand corresponding voltage drop of the constant-current source and calculating to obtain a direct-current resistance value. A short-circuit impedance testing module is used for conducting calculationon the sampled alternating-current voltage and the current value to obtain a short-circuit impedance value. An on-load tap switch testing module is used for carrying out signal sampling on the actionof an on-load tap switch, and calculating to obtain the waveform and the time of the transition resistance. The on-load tap switch testing module calculates to obtain the no-load voltage ratio and thegroup value of a transformer through respectively collecting a voltage signal on a high-voltage side and a voltage signal on a low-voltage side. The device is simple in structure, reasonable in design, convenient to operate, safe and reliable. The device can realize the measurement of the direct-current resistance, the variable-ratio group, the short-circuit impedance and the on-load tap switch test of a tested product.