The invention relates to a synthetic method and application of an Ni3N NSs/NF nanosphere, belonging to technical field of preparation of nanomaterials. The synthetic method comprises the steps of firstly synthesizing a nanowire array on Ni(OH)2/NF foamed nickel as a template by virtue of a 120-DEG C hydrothermal method, carrying out 90-DEG C oil bath self-catalytic reduction on a nanosphere arrayon Ni(OH)2/NF foamed nickel as the template, and carrying out calcining at 350 DEG C in an ammonia gas atmosphere, so as to obtain the nanosphere array on Ni(OH)2/NF foamed nickel. According to the Ni3N NSs/NF nanosphere prepared by virtue of the preparation method, UOR presents ultrahigh activity and stability in an alkaline solution and has excellent catalytic property and durability in HER, andthe voltage of a battery can reach 100mA cm<-2> only through a voltage of 1.423V (vs.RHE) in an alkaline double-electrode electrolytic tank, so that the Ni3N NSs/NF nanosphere can be taken as a duel-function catalyst for efficient urea oxidation and electro-catalysis hydrogen evolution.