To solve measurement problem of relative attitude and position for non-cooperative spacecraft in on-orbit capture, an autonomous measuring method for relative attitude and position of spatial non-cooperative spacecraft based on stereo vision was proposed. Main body of spacecraft and satellite-rocket docking ring were taken as recognition features in this method, and no staff was needed to participate in the recognition process; meanwhile, a feature matching method based on spatial geometry constraint was introduced. With the guidance of spatial geometry constraint, three-dimensional information of features was directly obtained at the time of completing matching to realize integration of feature matching and reconstitution; finally, the relative attitude and position of spacecraft were calculated according to spatial vectors, and calculation accuracy was improved via fully utilizing redundant information. Experimental result shows on condition of main body of spacecraft at 280 mm and relative distance at 2 m, attitude and position measurement error of the proposed method are less than 1.5° and 4 mm respectively, satisfying on-orbit capture measurement requirements of relative attitude and position for spatial non-cooperative spacecraft.