Because of the tiny contact area and thin lubricating film thickness of elastohydrodynamic lubrication(EHL),as well as the nonlinear viscoplastic property and strong nonNewtonian behavior of greases,it is difficult to measure the lubricating film thickness of grease EHL,and carry out the experiments of grease EHL.Based on optical interferometry,a grease EHL test bench was developed,and its mechanical transmission device,image capturing device,and grease reservoir and loading device were designed.The white light and monochromatic light interference experiments，Hertz dry contact and grease EHL experiments were carried out the designed test bench.The experimental results show the collected images by this test bench are clear and consistent.The monochromatic light interference experiment can measure the lubricating film thickness in a wider measurement range，and the image pattern by monochromatic light interference is clearer than that by white light interference.Theroratical calculation result is consistent with experimental result,indicating this test bench is suitable for experimental research of grease EHL.