The invention discloses an ejector plate mechanism, a powder cylinder and selective laser melting equipment. The ejector plate mechanism comprises an upper plate, a seal structure body and a lower plate from top to bottom. Each of the powder cylinder and the selective laser melting equipment comprises the ejector plate mechanism. A three-layer structure in which the upper plate, the seal structurebody and the lower plate are combined is adopted, the ejector plate mechanism of the powder cylinder is stable in structure, and stress is balanced; in addition, an abrasion resisting ring small in friction coefficient is further arranged, friction between the ejector plate mechanism and a cylinder body is reduced, friction between the ejector plate mechanism and the cylinder body is not frictionbetween metal, abrasion of the ejector plate mechanism is reduced, abrasion resistance and sealing performance of the ejector plate mechanism are greatly improved, and the service life of the ejectorplate mechanism is greatly prolonged.