The invention belongs to the technical field of nuclear fuel element machining, and particularly relates to a grid tray part machining method. The outline of a whole clamping groove and bevel angle machining tool is cuboid, the front surface and the rear surface of the machining tool are provided with match-head-shaped through grooves B in a penetrating mode, the left surface and the right surfaceare provided with match-head-shaped grooves A in a penetrating mode, and a threaded hole is vertically machined in the upper surface so that a pressing screw can be tightened; after grid tray outlinemachining and match-head outline cross-section sheet machining are completed, match-head outline cross-section sheets are inserted in the grooves A, through tool aligning, it is ensured that a grid tray coincides with the center of the tool and is pressed through the pressing screw, the tool makes contact with the table top of wire-electrode cutting equipment and is horizontally placed and pressed by a pressing plate, grid tray clamping groove structures are machined at the grooves B, and clamping groove machining is completed; and after clamping groove machining is completed, the tool is turned over by 90 degrees, the tool makes contact with the table top of wire-electrode cutting equipment and is horizontally placed and pressed by the pressing plate, and bevel angle machining is completed. The grid tray part machining method can meet the machining requirements for grid tray parts.