NOVELTY - Preparing alkaline power battery foamed substrate comprises (i) adding a foaming agent into the solution of polyurethane raw material to obtain polyurethane sponge; (ii) dipping the polyurethane sponge in polyester solution so that polyester covers complete surface of the polyurethane sponge bubbles; (iii) subjecting the polyurethane sheet to magnetron controlled vacuum sputtering nickel plating; (iv) subjecting polyurethane sheet to electroplating using sulfate electroplating solution; and (v) reducing and sintering under hydrogen atmosphere.    USE - The method is useful for preparing alkaline power battery foamed substrate.    ADVANTAGE - The method improves the crystal lattice structure of the substrate (claimed). The foamed substrate has high capacity, good charge/discharge efficiency, and ensures discharge of large amount of current.    DETAILED DESCRIPTION - Preparing alkaline power battery foamed substrate comprises (i) adding a foaming agent into the solution of polyurethane raw material to obtain polyurethane sponge, the polyurethane sponge is 1 square inch with 70 consecutive pores, the thickness is 1.2 mm and the elastic deformation amount is more than 15%; (ii) dipping the polyurethane sponge in polyester solution so that polyester covers complete surface of the polyurethane sponge bubbles; (iii) subjecting the polyurethane sheet to magnetron controlled vacuum sputtering nickel plating, where the current is 10-30 A, the vacuum degree is 0.1-1 Pa, and the speed is 1.5 m/minute; (iv) subjecting polyurethane sheet to electroplating using sulfate electroplating solution, where the temperature is 45-50 degrees C, the pH is 4-5 and the sulfate electroplating solution contains 180-300 g/l nickel sulfate, 20-50 g/l nickel nitrate, 30-45 g/l sulfonic acid and 0.04-0.06 g/l tetraphenylporphyrin copper impurity masking agent; and (v) cleaning foamed nickel remain in the mold core by high temperature oxidation at 600-640 degrees C for 30-40 minutes, and reducing and sintering under hydrogen atmosphere at 900-950 degrees C 50-60 minutes, where the flow rate of gas is 30-35 m3/hour.