The invention provides a coin multi-channel weight separation inventory finishing machine and a method thereof. The invention comprises a transfer mechanism, a separation inventory mechanism and an organizing mechanism, wherein the mechanisms are provided with a number of inner rails. The transfer mechanism is inclined upward. The transfer mechanism, the separation inventory mechanism and the organizing mechanism are connected in turn. The separation inventory mechanism is inclined downward. The transfer mechanism comprises a conveyor belt and a shunt height limiting device. The conveyor belt is connected with a power supply. The shunt height limiting device comprises a rail separating plate and sub rail plates. The separation inventory mechanism comprises infrared counters, guide slopes, separation rails and drop-holes. Each drop-hole is located on the lower end of a separation rail. The diameters of the drop-holes successively diminish with the set height of the separation rails. The guide slopes and the separation rails are assembled in a staggered manner in the shape of oblique Z. A guide slope transfers a coin from a drop-hole to a separation rail of a next layer. According to the invention, separation, inventory and organizing of large batches of coins can be efficiently completed, and foreign bodies can be separated.