The system of 3D laser scanning mainly consisting of 3D laser displacement sensor,laser line source,coded tensile displacement sensor and stepper motor was introduced.The system was applied in the measurement of 3D graphics,round beating of a location,cylindricity and axis straightness.The structure and principle of 3D laser scanning systems were introduced and the measurement process was established for the estimation of cylindricity error.A measurement software was designed based on the software developing platform LabVIEW.