Abstract: The residual stress of stress-free powder, fine-grained material and large-grained material was tested by different collimator diameters and different swing angles, the influencing factors of residual stress test results were studied. The results show that different collimation tube diameters and different swing angles had little effect on the residual stress test results of stress-free powder and fine-grained materials, but had a great influence on the residual stress test results of larger grain materials. Using a larger diameter of the collimating tube and increasing the swing angle could improve the peak shape and symmetry of the diffraction peak of the larger grain material and improve the accuracy of the test results.