The invention relates to the technical field of waste lithium battery recycling. The invention discloses a method for preparing high-purity NCM salt by recycling waste lithium batteries. The method comprises the following steps: S1, a pretreatment process, the pretreatment process mainly comprises the following steps: carrying out crushing, screening, leaching, impurity removal and other pretreatments on each waste lithium battery raw material, including the steps of crushing and screening, leaching reaction, iron and aluminum removal, washing and filter pressing and the like; and S2, an extraction procedure: the procedure comprises the procedures of copper extraction, manganese extraction, cobalt extraction, nickel extraction and the like, a filtrate treated in the pretreatment procedureis mainly extracted, copper, manganese, cobalt, nickel and other metal elements are extracted, and a copper sulfate solution, a lithium sulfate solution, a manganese sulfate solution, a cobalt sulfatesolution and a nickel sulfate solution are obtained after extraction. According to the process technology, material consumption is reduced, the resource utilization rate is increased, efficient recycling of metal resources such as nickel, cobalt and manganese is achieved, the yield of nickel, cobalt and manganese can reach 98%, and the yield of copper and lithium can reach 90%.