The invention provides a test device used for spring safety valve dynamic characteristics and a test method used for the spring safety valve dynamic characteristics, belongs to the technical field ofvalve test, and is mainly used for testing the open, discharge and return characteristics of the safety valve. The whole test device comprises an air supply device, a pressure stabilizing device, a quick start and stop device, a pipeline air pressure detection device, a pipeline air mass flow detection device, a safety valve stem displacement detection device, a safety valve system, a test table,a pipeline support and an acquisition system. The pressure stabilizing device is used for stably regulating the air pressure in the pressure vessel. The quick start and stop device is used for controlling opening and closing of the pressure vessel. The pipeline air mass flow detection device is used for detecting the mass flow of the air in the pipeline. The safety valve stem displacement detection device is used for detecting the displacement change of the safety valve stem. The acquisition system is used for acquiring, processing and saving the experimental data. The device is simple in structure and high in accuracy so as to guarantee the test of the safety valve dynamic characteristics.