The utility model belongs to the field of industrial control and particularly relates to a jet self-priming automatic thermostatic water mixing device. The water mixing device comprises a water mixer (1), a temperature control meter (9), an electromagnetic relay (10), an electric valve (11), a thermocouple and a spherical valve (13), wherein the thermocouple is mounted in a thermocouple mounting hole (12), close to a mixed water outlet (8), on the water mixer (1); the temperature control meter (9) is connected with the thermocouple and the electromagnetic relay (10); the electromagnetic relay (10) is connected with the electric valve (11). Based on the design scheme of a traditional water mixer, the jet self-priming thermostatic water mixing device dispenses with the traditional manual water temperature adjustment mode, realizes thermostatic control through the feedback principle so as to achieve automatic temperature control, and is relatively low in errors and relatively high in precision; within the normal work cycle, the adopted electric valve cannot be opened and closed until the hot water flow rate needs to be adjusted, so that electricity and energy are only consumed in a very short time, and accordingly, the energy-saving and emission-reducing effect is achieved.