Processing method of high-precision stainless steel casting

The invention discloses a machining method of a high-precision stainless steel casting. The machining method comprises the steps that a clamp suitable for a high-precision stainless steel casting product in shape is provided; the product is of a shell structure with a front face, a back face and side faces. The clamp comprises a first station, a second station and a third station; the clamps are installed on a first station area, a second station area and a third station area of a gap bridge plate of the four-axis machining center respectively; the front face of the product faces downwards and is clamped on a first station through a product tool, the product and the product tool are accurately positioned and pressed through a clamp, and a positioning reference boss on the back face of the product is machined; the product and the product tool are moved to a second station to be positioned and fixed, and the front face of the product is machined; and the product and the product tool are moved to a third station