A hydrogen fuel cell is a conversion device that converts hydrogen energy into electrical energy. The main factors restricting the large-scale application of hydrogen fuel cells in automobiles are the lifetime and durability of fuel cells. At present, there are few studies on fuel cell durability tests, and the existing test methods have shortcomings, such as narrow coverage of working conditions and short duration. Based on national and industry standards, this paper designs a test method and conducts durability tests for a fuel cell system, and the test results show that after 1200 hours of testing, the average cell voltage degradation of the fuel cell system under the reference current is 4.86%. At low power condition, this degradation is around 4%. As the system output power increases, the degradation gradually increases. At high power condition, the degradation is around 10%. This paper accumulates experience for the durability test of fuel cell system and provides support for the establishment of durability evaluation system.