Abstract: As a green solvent, the deep eutectic solvent has attracted increasing attention in the field of recycling valuable components of waste lithium batteries. In this paper, the waste lithium manganate battery cathode powder was taken as the object for lithium and manganese leaching using deep eutectic solvent of guanidine hydrochloride and lactic acid. The effects of leaching temperature, leaching liquid solid ratio and leaching time on the leaching rate of lithium and manganese were investigated. The results showed that the appropriate dissolution conditions were as follows: using deep eutectic solvent with the mole ratio of guanidine hydrochloride to lactic acid 1∶2, the volume mass ratio of leaching solution to solid was 10 mL/g, the dissolution temperature was 70 ℃, and the leaching time was 1 h. Under the appropriate dissolution conditions, the leaching rate of lithium and manganese in lithium manganate cathode powder reached to 99.27% and 99.20% respectively.