The invention relates to a ball grinding tank. The ball grinding tank comprises at least two tank bodies which are fixedly connected. A plurality of ball grinding units are formed between every two adjacent tank bodies and are independent sealing cavities. The ball grinding tank comprises the multiple ball grinding units, and ball grinding treatment of a plurality of batches of material samples can be finished at a time. Cooperative vibration can be achieved among the multiple ball grinding units, so that the ball grinding efficiency is greatly improved. Furthermore, the sample yield for ball grinding of a trace of or a small number of samples can be guaranteed through the design of the multiple ball grinding units, and meanwhile due to the fact that the ball grinding units are in the same ball grinding condition, the experiment repeatability and consistency of the whole experiment can be guaranteed through the ball grinding tank.