The utility model relates to a water lubrication rubber tail bearing and machinery sealing performance test device which is a device capable of simultaneously coupling a back tail bearing (6) with a machinery sealing and testing performance of a water lubrication rubber tail bearing and the machinery sealing. The test device comprises a driving mechanism, the machinery sealing, a loading mechanism (5), a pressure ratio adjusting mechanism and a water supplying mechanism, wherein the driving mechanism is arranged at a left end of an experiment station, the load mechanism (5) is arranged in front of the back tail bearing, the water supplying mechanism is independently arranged beside the test station, a high-pressure water pipe (25) is connected with a high-pressure water tank (8), the machinery sealing is mounted at a tail end of a tail shaft (4), and the pressure ratio adjusting mechanism is mounted at a tail end of the high-pressure tank. The test device is simple to operate, is easy to realize, is further accurate and reliable, can simultaneously carry out coupling tests on the water lubrication rubber tail bearing and the machinery sealing under the complex conditions of different speeds, courses, depths, water qualities and water temperatures, and does not generate any axial pressure on the tail shaft when the water pressure changes.