The purpose of this study is to find the ultimate strategy to solve the cold start problem when fuel cell vehicles or fuel cell backup power stations in the low-temperature environment for long-term after its shutdown, this paper uses hydrogen catalytic combustion auxiliary heating cold start strategy, which puts hydrogen and air in the external catalytic reactor for catalytic combustion, and then puts the hot mixed gas into a fuel cell cathode flow field and water flow field. Subsequently, a auxiliary PEMFC strategy cold start test platform has been established based on catalytic combustion. Finally, the airspeed, hydrogen concentration and other conditions affect have been researched. Finding that increasing the hydrogen concentration and airspeed of the reaction mixture can shorten fuel cell start time. When the space velocity is 3L/min, hydrogen volume concentration is 4%, the fuel cell internal temperature can rise to zero degrees centigrade from minus ten degrees centigrade within 600 seconds.