In order to improve sealing performance and reduce the surface roughness of miniature cone seal pair, a small cone seal pair grinding device controlled by MCU was developed. With vertical layout scheme, the device mainly composed of rotating grinding mechanism, lifting mechanism, locating and clamping mechanism and frame. The working principle of the device was briefly described. According to the functions of every mechanism, their structures were designed. STC89C52 MCU was selected as the control system, and the device was driven by the stepping motors. Using the device, sealing performance of small cone seal pair and the efficiency are improved.