The utility model provides a power supply system, it includes: be connected through the cable between the main control system and integratedly respectively set up the conversion module in each measuring and control equipment, main control system and each measuring and control equipment, including the integrated AC that is provided with in the main control system DC power and first communication circuit, AC the DC power -on is crossed the cable and is supplied power to each measuring and control equipment, and first communication circuit passes through cable and each measuring and control equipment data transmission, is conversion module with AC offer place measuring and control equipment after the conversion of the power supply voltage of DC power, the integrated second newsletter circuit that is provided with still among the measuring and control equipment, the second newsletter circuit passes through cable and the transmission of first communication circuit data, the cable includes the sheath and is arranged in the power supply transmission line and the data transmission line of sheath. The utility model discloses a total unified power supply mode of line type, it can be savedAC power supply circuit and dispose the cost. And simultaneously, the utility model discloses an unified four -core connecting wire and waterproof quick connecting terminal to a convenience of the ystem installation maintenance is provided.