The invention discloses a fuel battery low-temperature starting grading preheating control method. According to the fuel battery low-temperature starting grading preheating control method, an electric pile, a sensor for measuring the temperature of the electric pile, a fuel supply system, an oxidizing agent supply system, a cooling medium circulating medium, an electric pile power output circuit, an external heat source heating system, an internal heat source heating system and a total control system are provided, wherein the external heat source heating system utilizes a mode of directly heating the electric pile by an electric heating wire, or a mode of circularly heating the electric pile after a cooling medium is heated or a mode of heating the electric pile after the air is heated; and the internal heat source heating system utilizes heat generated by electrochemical reaction of the electric pile or heat generated by catalytic combustion in the electric pile. According to the method, the preheating mode of the electric pile is determined based on a change relation between supercooling degree and the induction time of liquid water icing influenced by a porous medium material component and a microporous structure and according to the environment temperature of fuel batter low-temperature starting, safe, rapid and efficient starting of the electric pile is guaranteed, and the durability of the electric pile is improved.