The invention provides equipment for preparing a large-area antimony selenide film and a method and application of the equipment. The equipment is characterized in that a cylinder is horizontally fixed in a deposition chamber of deposition equipment; one side of the cylinder is communicated with an argon gas supply pipe, and a strip hole extending in the horizontal direction is formed in the otherside of the cylinder; a cylindrical net leak part for containing antimony selenide particles is coaxially arranged in the cylinder, and one end of the net leak part is connected with a rotating shaftand can rotate in the cylinder; a sample table is arranged at the position opposite to the strip hole, the sample table is connected with a lifting rod and can move up and down along with the liftingrod; a substrate is arranged on the table surface, opposite to the strip hole, of the sample table; and a baffle plate is arranged between the sample table and the cylinder. According to the equipment, the large-area antimony selenide film with good crystallization state, high film forming uniformity and relatively small defect density is prepared by regulating and controlling the upper and lowermovement times of the substrate, the temperature of the substrate and the temperature of the source and the gas flow of introduced high-purity argon; and the equipment and the process are simple, andthe large-area antimony selenide film is beneficial to popularization and application.