The invention discloses a self-adaptive stealth system and method for a square cabin. The system comprises projection devices and cabin surface brightness detection devices which are arranged on sidesurfaces and a top surface of the square cabin, image acquisition devices and environment brightness detection devices which are arranged on the side surfaces of the square cabin, the system further comprises a projection control module and a brightness control module, wherein the projection control module is used for projecting environment images onto the side surfaces and the top surface of thesquare cabin, and the brightness control module is used for adjusting projection brightness. The method comprises the following steps that a plurality of environment images around the square cabin arecollected in real time, for any side surface, an ambient image which is opposite to the side surface is projected onto the side surface, and brightness of projection is adjusted by utilizing the brightness of the side surface and the brightness of the environment; the image which is facing the side surface is projected to the top surface of the square cabin, and the projection brightness of the top surface is adjusted by utilizing the brightness of the top surface and the brightness of the environment. According to the self-adaptive stealth system for the square cabin, the square cabin can beintegrated with environment anytime and anywhere, and the system has the outstanding advantages of being high in environmental adaptability, good in fusion effect, low in cost and the like.