The ultraviolet aging tester uses fluorescent ultraviolet lamps as the light source, and performs accelerated weather resistance tests on materials by simulating the ultraviolet radiation and condensation in natural sunlight to obtain the results of the weather resistance of the materials. It can simulate environmental conditions such as ultraviolet, rain, high temperature, high humidity, condensation, darkness, etc. in the natural climate. By reproducing these conditions, they can be combined into a cycle and let it automatically execute the cycle times.