The present disclosure provides a fixture for fixing a steering knuckle in a machining process, the fixture comprises a bottom plate, wherein the bottom plate is machined with two bottom plate windows that are configured to accommodate machined parts of the steering knuckle; three groups of pressure claws and three groups of locating pins are fixed on the bottom plate, and the pressure claws and the locating pins are respectively fixed to the through holes of the bottom plate; and the three groups of pressure claws are respectively arranged at three vertexes of a triangle.