The invention discloses a grinding fixture. The grinding fixture comprises a transmission box and a clamping component, wherein the clamping component comprises a clamping rod, a rotary shaft, a rotary disc and an elastic compaction disc; a slide rail is arranged in the transmission box; the rear end of the clamping rod is matched with the slide rail, and the clamping rod is vertical to the sliderail; a limit block is arranged outside the rear end of the clamping rod; compaction springs are arranged at the two sides in the transmission box; the compaction springs are connected with the clamping rod; a connection sleeve is arranged at the front end of the clamping rod; the connection sleeve is fixedly connected with the clamping rod and vertical to the clamping rod; a sleeve and a self-aligning bearing are arranged in the connection sleeve; one end of the rotary shaft is installed in the connection sleeve; the sleeve and the self-aligning bearing are adaptive to the rotary shaft; the other end of the rotary disc is connected with the rotary disc; and the elastic compaction disc is fixedly connected outside the rotary disc. The grinding fixture disclosed by the invention is used forclamping a rotary body, and the rotary body is capable of freely rotating on the fixture, so that grinding machining is facilitated.