The invention designs a novel automatic ball adding machine which is suitable for adding balls into ball milling machines with various specifications, such as lattice-type ball mill, overflow type ball mill, semi-autogenous grinding ball mill, etc., and is accurate in ball adding amount, stable, and low in failure rate. The automatic ball adding machine provided by the invention comprises a ball adding barrel, a ball adding storehouse, a buffer area, a motor, a disc ball unloading machine and a ball uploading pipe. The automatic ball adding machine provided by the invention can effectively prevent occurrence of squeezing, stacking and blocking among the balls during a ball adding process, so that ball loading and unloading processes during a ball adding operation are quite smooth, and a ball adding number can be further calculated, thereby effectively improving ball adding efficiency. In addition, the ball adding machine is simple in structure, low in manufacture cost, convenient to maintain, and extremely low in failure rate, and is suitable for popularization and application in the ball adding process of the ball milling machines with various specifications.