The invention relates to a steamer power plant closed air screen cold-proof heat-insulation extra large gate structure comprising a gate frame body and a wind-proof steel gate arranged outside the gate frame body; the inner side of the gate frame body are provided with at least two layers of air cold-proof roller shutters; a first gap is reserved between the air cold-proof roller shutters and the wind-proof steel gate; a second gap is formed between the air cold-proof roller shutters, thus forming a dual-layer or multilayer air heat insulation structure; the ground outside the gate frame body is a down slope, so a cold bridge can be prevented in outdoor; the connecting portion between the surrounding of the wind-proof steel gate and the gate frame body is provided with a sealing strip, thus forming an annular sealing insulation structure. The surface of an existing gate body is wrapped by an insulation layer, thus enlarging gate body thickness and size, and the gate is hard to be opened/closed, poor in sealing performance, and poor in insulation effect; the steamer power plant closed air screen cold-proof heat-insulation extra large gate structure can solve said problems, is small in gate size, convenient to open/close, good in sealing performance, and excellent in insulation effect.