Abstract: A large amount of barium slag accumulation will cause great harm to the environment. The use of hydrochloric acid leaching for barium residue can effectively recover the residual soluble barium salt in the barium residue and greatly reduce the harm of the barium residue to the environment. It is a better method to utilize the barium residue. Through experiment, this paper obtained the better barium slag hydrochloric acid leaching conditions, the barium slag grinding fineness is 0.074 mm accounted for 80%, hydrochloric acid concentration is 3 mol/L, leaching solid-liquid ratio is 1∶7, leaching time is 2 h, leaching temperature of 40 ℃, leaching mixing speed is 480 r/min, obtained the best barium ion leaching rate, barium ion leaching rate reached 38.88%. When only soluble barium salt is considered, the leaching rate of barium ion reaches 90.30%.