Abstract： The spatial registration serves is a pivotal step for surgical navigation systems to establish the transformation relationship between surgical and image spaces.In response to the complexities and time-consuming nature of existing surgical navigation systems,we proposed a spatial registration method based on encoded speckle structured light.A speckle template containing circular dot spots of different radii was designed for the reconstruction of surgical space point clouds,and the spatial registration was completed through the coarse to fine point cloud registration with the image spaces.Experimental results demonstrated that this approach significantly enhanced overall registration efficiency while ensured a high level of spatial registration accuracy,with an average registration time of less than 10 s and accuracy of(0.89±0.08)mm for all target points.This can meet the application requirements in surgical navigation.