The objective of the invention lies in providing a test bench for the comparison of working conditions of a seal ring, wherein the seal ring is disposed in a trench which is matched with an oil distribution sleeve, and a seal ring test device is assembled according to a drawing. During a test, oil is injected into an oil pipe through a hydraulic oil source, so as to enable a pressure to be within a pressure range when the seal ring is in use. Moreover, the rotating speed of a transmission shaft is adjusted so as to enable the seal ring to be within the rotating speed range. The static and dynamic leakage volumes of an oil cavity where the seal ring is located are checked through the measurement of an oil outflow volume of an oil outflow pipe. The service life of the seal ring is examined according to the corresponding time, rotating speed and pressure, which are set in a testing schedule of the seal ring. Through the testing of seal rings made of different materials, the using effects of the seal rings made of different materials are compared with each other. The test bench just needs one driving motor for testing two sets of seal rings at the same time. The comparison test of simulating the seal rings made of different materials under the same working condition enables the test results to be more real and reliable.