The invention relates to a silver and copper composite belt vacuum hot pressing process. A hot pressing device is used for performing machining, and comprises a furnace body, a vacuum pump, a hot pressing die, a die supporting base and a supporting pressure spring; an electric heating element is arranged in the furnace body; the hot pressing die comprises a pressing barrel, a pressing head and a pressing rod; a center hole of the pressing barrel is composed of an upper extruding hole and a lower extruding hole; the pressing head is arranged over the pressing barrel; the upper end of the pressing head is connected with the pressing rod; the upper end of the pressing rod stretches out of the furnace body and is in transmission connection with a power source; and the pressing head is pushed by the pressing rod and can stretch into the center hole of the pressing barrel. According to the silver and copper composite belt vacuum hot pressing process, by means of the taper of the center holeof the die, silver and copper can be connected together in a hot pressing diffusion manner in a vacuum environment, and a high quality silver and copper composite belt can be prepared.