The invention relates to a preparation method of powder rubber. The preparation method comprises the following steps of: simultaneously adding an isolating agent and a flocculant solution into an organic solvent, sufficiently stirring at the room temperature to form a diffusion system, subsequently further stirring, and at the same time slowly adding rubber emulsion, further separating, washing, eluting and drying so as to obtain the powder rubber. The prepared powder is uniform in rubber particle, non-sticky, free of caking when being stored, rapid to powder and high in production efficiency, and moreover as non-toxic or low-toxicity solvents are adopted as the organic solvent, the powder rubber can be effectively recycled and reused after being used, thereby being small in loss and harmless to the environment. The powder rubber is applicable to powdering processes of rubber latex with/without gel and high Mooney viscosity or low Mooney viscosity.