Making method of round granule zinc boron potassium fertilizer

The invention discloses a making method of a round granule zinc boron potassium fertilizer. The method is characterized by: in the process of granulation, mixing zinc sulfate, sodium borate and an auxiliary material with potassium sulphate uniformly according to certain proportion, and sending the mixture into a granulation machine for granulation so as to obtain a round granule potassium fertilizer with a K2O content of 40%-47%, a zinc content of 1%-2%, and a boron content of 0.1%-0.5%, then coating the round granule potassium fertilizer with a layer of a degradable slow-release material containing zinc and boron, thus obtaining the round granule zinc boron potassium fertilizer with slow release performance. The method provided by the invention combines internal adding with external wrapping, adds zinc and boron elements needed by plant growth into the granule potassium fertilizer, and simultaneously wraps the granule fertilizer surface with nutrient elements to endow the fertilizer with slow release perform