The invention discloses a waterborne zinc stearate emulsion, and a preparation method and application thereof, belonging to the technical field of zinc stearate. The waterborne zinc stearate emulsion comprises, by mass, 30 to 38% of zinc stearate, 5 to 9% of an emulsifier, 3 to 8% of a dispersant, 0.2 to 0.7% of an antifoaming agent, 0.2 to 0.5% of an antiseptic and 44.4 to 61.4% of water, summing to 100%. According to the invention, the non-ionic emulsifier with an HLB value of greater than 13 is selected and used, and the zinc stearate emulsion with few bubbles, stable emulsion and high solid content is prepared through natural emulsification, assistant mechanical emulsification and usage of other appropriate auxiliary agents; the preparation method is simple and easy to operate and needs no high temperature, high pressure and other conditions, which is beneficial for reduction in production cost; and the prepared zinc stearate emulsion has small viscosity, can maintain stable performance when stored for a long time and can be applied to industries like rubber, plastics, paint, thermal sensitive paper and cosmetics.