The invention relates to an automatic functional test device of a coffee maker. The automatic functional test device comprises a water supply mechanism, a coffee bag prosthesis supply mechanism, a needle valve, a water outlet valve, a flow meter, a temperature sensor, a pressure sensor and a control system. The water supply mechanism is used for filling water into the coffee maker to be tested and comprises a water tank and a port connected with the water tank. The coffee bag prosthesis supply mechanism is used for placing a coffee bag prosthesis into the coffee maker to be tested. On a test water path of the coffee maker to be tested, the needle valve is located on the downstream of the coffee bag prosthesis, the water outlet valve is located on the downstream of the needle valve, the flow meter is located on the upstream of the coffee maker to be tested and arranged between the water tank and the port, the temperature sensor is located on the coffee bag prosthesis, and the pressure sensor is located between the coffee bag prosthesis and the needle valve. The control system controls the water supply mechanism and the coffee bag prosthesis supply mechanism to act, receives signals emitted by the flow meter, the temperature sensor and the pressure sensor and outputs the signals after processing the signals. The test device is high in test efficiency, low in labor intensity and capable of ensuring the quality of products which are massively produced.