High and cold high-altitude environment simulation device and method for testing electronic and electrical equipment

The invention discloses a high-cold and high-altitude environment simulation device and method for testing electronic and electrical equipment, and belongs to the technical field of environment applicability testing of the electronic and electrical equipment. The high-cold and high-altitude environment simulation device comprises an external air connecting header pipe, a liquid nitrogen tank and an environment simulation testing room, and a six-degree-of-freedom vibration simulation platform and a fan are arranged in the environment simulation testing room; a rainwater generating device and an ice and snow generating device are arranged on the top frame, and a side wall opening is connected with a pressure adjusting device; an inlet of the external air connecting header pipe is communicated with an external environment, an outlet of the external air connecting header pipe is connected with a first input port of the mixer, an outlet of the liquid nitrogen tank is connected with a second input port of the mixer