The utility model provides a smoke exhaust device for civil air defense engineering. The utility model belongs to the field of smoke exhaust devices, the middle pipe is connected between the first arc-shaped pipe and the second arc-shaped pipe; fans are mounted in the first arc-shaped pipe and the second arc-shaped pipe; net rack is arranged in the first arc-shaped pipe, filter screen is laid on the screen frame, two baffle plates are arranged in the second arc-shaped pipe; a filling pipe is connected between the two baffles; the filling pipe is filled with activated carbon particles; a mounting pipe positioned at the pipe hole is connected between the upper mounting plate and the lower mounting plate; vent holes are formed in the side walls of the mounting pipes, filter bags are arrangedon the inner side walls of the mounting pipes, a movable ash collecting bin is arranged on the bottom surface of the lower mounting plate, an opening is formed in the side wall of the middle pipe, a sealing plate is mounted at the opening, and a connecting rod is connected between the sealing plate and the movable ash collecting bin; the smoke exhaust device solves the problem that an existing smoke exhaust device is lack of purification of dust and toxic gas in the smoke exhaust process.