An inspection system for coaxiality of multiple circles is presented,which uses the non-diffraction laser beam as the inspection reference.The system principle and structure are introduced.A test scheme of coaxiality is carried out with a camera (640 pixel×480 pixel and 0.050 4 mm/pixel as resolution of the target) and at different distances of 5 m,15 m and 24 m.The test results show that the standard deviation for x direction is 0.019 3 mm,0.026 2 mm and 0.042 8 mm respectively,and that for y d...