The invention discloses selective laser sintering and melting equipment which comprises a sealing forming bin, a laser galvanometer arranged outside the sealing forming bin, a lens arranged on the surface of the sealing forming bin and used for enabling the laser projected from the laser galvanometer to enter the sealing forming bin, a part machining platform arranged in the sealing forming bin, a powder paving scraper used for paving powder on the machining platform, an annular gas curtain device fixed to the inner wall of the sealing forming bin and corresponding to the lens, and a gas source used for providing gas for the annular gas curtain. According to the selective laser sintering and melting equipment, a cone high-speed gas curtain wall can be formed around the inner surface of the lens, a clean space is formed around the inner surface of the lens, and metal powder in the forming bin can be effectively prevented from adhering to the surface of the lens. Meanwhile, the lens is prevented against dust and cooled through inert gas in the forming bin during the machining process of the equipment, so that a large amount of inert gas is saved, and the production cost is lowered.