The invention provides a method for manufacturing a non-linear crystal gallium selenide component, relates to a method for manufacturing crystal components, and aims to solve the technical problems that existing GaSe crystal has low transmittance and is easily deformed and split when being used. The method comprises the following steps: 1, etching the surface of GaSe crystal ingot, cleaning and drying; 2, putting the crystal ingot into a boat, putting the boat in the middle of a quartz tube, and putting GaSe polycrystal powder at two ends of the boat; or putting the GaSe polycrystal powder at one end of the boat, and putting Se at the other end of the boat; vacuumizing the quartz tube, sealing, and putting into a resistance furnace in a single-temperature region; 3, annealing; 4, cutting the annealed crystal ingot, and trimming to form a GaSe crystal block along the C-axial direction; and 5, fixing the GaSe crystal block at the hole of a metal base with glue, coating a polytetrafluoroethylene coat, adding an upper cover, and connecting the base and the upper cover with a fixed nut to obtain a GaSe component. The component can be used in a laser.