Film extraction device based on negative pressure adjustment

A first static pressure air bellow and a second static pressure air bellow are arranged on the upper side and the lower side of a film passing opening of a process liquid tank respectively, a negative pressure fan is started, a pressure regulating valve is started, and under the action of the negative pressure fan, the film passing opening of the process liquid tank is subjected to film extraction through the first static pressure air bellow and the second static pressure air bellow. Gas around the film passing opening of the process liquid tank is sucked into the first static pressure air bellow and the second static pressure air bellow, a local negative pressure area is formed around the film passing opening, and when an organic solvent in the process liquid tank volatilizes, the organic solvent can flow into the negative pressure area of the film passing opening under the action of pressure difference; the air is sucked by the first static pressure air bellow and the second static pressure air bellow, flow