The invention discloses a fuel cell parameter control system. The fuel cell parameter control system mainly comprises an air compressor, a pressure reducing valve, a pressure gauge, a filter, a gas supply control valve, a flow meter, a humidification path control valve, a humidifier, a water supplying control valve, a water replenisher, a manually operated valve, a dry gas path control vale, a pressure sensor, a temperature sensor, a fuel cell stack, a pressure sensor, a back pressure valve, a water tank, a PC end control and display device, a hydrogen cylinder and a nitrogen cylinder. The system can test a single parameter of a fuel cell stack system, has a safe use method and stable performances, can detect the performance parameters of the fuel cell under a single variable, and realizes accurate and comprehensive detection of cell stack performances. After a test reaction of the fuel cell, only water is produced and any pollutants are avoided so that zero discharge of pollutants is realized. The invention also provides a working method of the fuel cell parameter control system.