Abstract Elastohydrodynamically lubricated conjunctions are often subjected to impact loading. In such case the squeeze effect plays an important role. This research uses a self-development EHL tester to explore the effects of squeeze velocity, load and viscosity of lubricant on the dimple film thickness occurs between two components approach each other. The contact region is studied by means of optical interferometry using white light, a microscope and a CCD camera recording equipment. The results of the test show that increasing squeeze velocity makes the dimple deeper. Furthermore, the maximum central dimple film thickness becomes greater as the viscosity of lubricant increases at the same experiment condition. When the squeeze load is larger, it will keep the dimple film longer.