The invention provides a power dividing method of a compound power source fuel cell hybrid energy system of an electric automobile. The method includes the steps that firstly, when a fuel cell is started, a fuel cell controller acquires the fuel cell voltage at the initial moment and the fuel cell current at the initial moment and acquires the fuel cell voltage and the compound power source voltage at every next moment; secondly, a discrete prediction model of the compound power source fuel cell hybrid energy system is established, and the power of the fuel cell at the next moment is determined; and thirdly, the reference output power of a storage battery at the next moment and the reference output power of a super capacitor at the next moment are further determined, and power division isachieved. By the adoption of the method, the demanded power of the whole automobile is optimized and divided, the defect that the fuel cell is slow in dynamic response is overcome, meanwhile power losses of a compound power source are reduced, the work efficiency of the compound power source is improved, the dynamic property requirement of the automobile is met, and the driving mileage of the automobile is increased.