The invention discloses a great-cycle overflow drainage device for a diamond wire slicing machine, and relates to the technical field of diamond wire cutting machines. The great-cycle overflow drainage device comprises a machine body and a water tank arranged on one side of the machine body. The bottom of the water tank communicates with an overflow device through a water outlet pipe. The overflowdevice comprises a transition box communicating with the water tank. The side, away from the water outlet pipe, of the transition box communicates with an overflow pipe. A filter piece is arranged inthe transition box, is in a ring shape and divides the transition box into an inner layer and an outer layer. One side of the inner layer communicates with the water outlet pipe. The bottom of an inner pipe communicates with a dirt outlet pipe, and the outer layer communicates with the overflow pipe. According to the great-cycle overflow drainage device for the diamond wire slicing machine, the water volume needed during slicing can be better controlled, influences possibly caused on slicing due to the silicon powder concentration are reduced, and the water circulation utilization rate is increased.