The invention relates to an aqueous zinc ion battery positive electrode material and a matched electrolyte. A chemical formula of the positive electrode material is RxKyMn1-xO2-z, wherein x is greater than or equal to 0 and less than or equal to 0.1, y is greater than or equal to 0 and less than or equal to 0.5, z is greater than 0 and less than 0.1, and R is a metal cation. A preparation process comprises the following steps: grinding and uniformly mixing potassium permanganate, manganese acetate tetrahydrate and metal salt, then putting a mixture into a tubular furnace, carrying out heat treatment under a protective atmosphere, washing an obtained product with deionized water, carrying out suction filtration for several times, and then drying the product in a drying oven to obtain the RxKyMn1-xO2-z positive electrode material. According to the invention, K<+> is successfully pre-embedded into a tunnel structure of a manganese dioxide crystal through one-step heat treatment, metal cations are doped into the manganese dioxide crystal, and oxygen vacancies are introduced into the surface of the manganese dioxide crystal so that the structural stability of manganese dioxide is improved, active sites are increased, and the conductivity is improved. The material is low in production cost, simple in process, mild in reaction condition and easy for large-scale preparation. The positive electrode material has a high specific capacity, a high rate capability and excellent cycling stability; and the matched and compatible aqueous electrolyte further prolongs the long cycle life of the positive electrode material.