Using carbon thermal reduction, water leaching process with sulfuric acid process for waste lithium ion battery cathode material of lithium nickel manganese cobalt leaching behavior of the four elements are studied, the results show that the carbon thermal reduction temperature 650 ℃, carbon thermal reduction time of 100 min, water temperature is 25 ℃, water leaching liquid-solid ratio of 12 mL?g-1, mixing speed is 100 rpm, water immersion time is 120 min, the leaching rate of lithium is 91.61 %;When sulfuric acid concentration is 2.0 mol?L-1, stirring speed is 200 rpm, liquid-solid ratio is 9 mL?g-1, leaching temperature is 75 ℃, and leaching time is 90 min, the leaching rates of Ni, Co and Mn are 95.83 %, 96.22 % and 98.02 %, respectively. This method is a more efficient way to recycle valuable metals from waste ternary lithium ion batteries.