Guide needle imbedding precision evaluation method

The invention discloses a guide needle implantation precision evaluation method which comprises the following steps: (1) scanning a to-be-implanted needle to obtain intraoperative 3D point cloud, planning a channel in the intraoperative 3D point cloud, controlling a robot to move in place according to the planned channel, implanting a guide needle, and scanning a needle implantation position to obtain postoperative 3D point cloud; (2) calculating gradient differences between all points in the intraoperative or postoperative 3D point cloud and one point in the 3D point cloud, taking the direction with the fastest gradient drop as the direction of the point, and taking the obtained gradient differences and the direction of the point as description vectors of the point; and (3) matching the intraoperative 3D point cloud with the postoperative 3D point cloud through the description vector, and calculating the deviation between the intraoperative planning channel and the postoperative needle placement position. Th