The invention discloses a comprehensive recovery method of a waste lithium manganate and lithium iron phosphate positive electrode material. The recovery method aims at solving the technical problemsthat in the prior art, the energy consumption is large, the energy utilization rate is low, certain potential safety hazards exist, meanwhile, the environment is greatly damaged, and process conditiondetails are difficult to control in the process operation process. The method comprises the steps of lithium iron phosphate powder size mixing, lithium manganate reduction leaching, lithium iron phosphate oxidation leaching, solid-liquid separation, washing, neutral impurity removal, alkaline impurity removal, concentration and sodium precipitation, and lithium precipitation, recovery of the waste lithium manganate and the lithium iron phosphate positive electrode material to obtain battery-grade lithium carbonate. The recovery method can be used for simultaneously recovering and treating thepositive electrode materials of the two waste lithium ion batteries; an oxidizing agent and a reducing agent needed in the prior art do not need to be added, high-temperature reaction is not needed,energy consumption is low, the energy utilization rate is high, meanwhile, the process is simple, the comprehensive recovery rate is high, the technological process is energy-saving, environment-friendly and high in safety, and high economic benefits are achieved.