Abstract:A method for measuring contact force of bearing roller based on digital speckle correlation method (DSCM) was proposed,which provides a basis of modifying the shape of bearing roller. A simple and reasonable set of positioning device was designed for roller positioning and loading system. Based on the software of development environment on MATLAB, the measurement software based on DSCM algorithm was built. In order to verify the effectiveness of the measuring system, the straight generatrix shape roller was measured. The contact strain distribution were in good agreement with the engineering experience and the calculating results of finite element method. Measuring four rollers on certain type bearing, under the different load condition, under the same load condition and double independent load condition, under the containing impurities condition, the trends of strain distribution were get. The test results show that the measurement system satisfies the requirement of the measurement test of roller contact force, and the system measurement results have good repetition, and the microscale change can significantly influence the distribution of contact force.