Abstract: For the location problem of curved surfaced parts in machining,CNC machine tool is used to measure the work-blank,and then the measurement data are matched with CAD models theo retical data.As a result the theoretical part is imbedded into the work-blank and the work-blank location is acquired.For the transform matrix solution,a chaos genetic hybrid a lgorithm is designed which can reduce the premasture probability of genetic a lgorithm and obtaing lobal optmial so lution.The experiments results indicate that the hybrid a lgorithm is effective in the solving transform matrix and the machining allow ance is optimized through mibed the thesry model into the work blank.