The present invention discloses a fixture used to adjust a valve housing position of a electrohydraulic servo valve which includes a component used to adjust valve housing, wherein a shoulder hole in one stage with its upside big and downside small is set on one end side of the servo valve; helical burr is set on lower hole wall face of the shoulder hole; the component that can adjust the valve housing includes an eccentric zero alignment pole with its external surface of top and bottom ladder-shaped and a tight nut that sleeved on the upper side of the eccentric zero alignment pole and pressed against the steps; the fixture includes a spanner component and a inner hexagon spanner; the spanner component is composed by a nut cover that can be placed inside the upper hole of the valve with a inner hexagon through hole on the end face that matches shape of outer surface of head of the tight nut and a handle that vertically connected to outer surface of nut cover; the inner hexagon spanner is inserted inside the hexagon blind hole of the eccentric zero alignment pole. The fixture that used to adjust valve housing position of an electrohydraulic servo valve is provided with advantages like simple structure, low production cost, easy usage, usage and reliable adjust result etc.