The invention provides an organic garbage treatment system with an automatic classification function. The organic garbage treatment system with the automatic classification function is used for carrying out classification treatment on kitchen garbage, and comprises a grinding-separating device, wherein the grinding-separating device comprises a cylinder block, a stirring device rotationally arranged in the cylinder block, and a spray device facing the interior of the cylinder block; a charge port is arranged in the upper part of the cylinder block; a discharge hole and an unloading port are arranged in the lower part of the cylinder block; the stirring device is used for grinding organic garbage into organic matter particles; a liquid sprayed by the spray device carries the organic matter particles and is rushed out from the discharge hole, and is subjected to resource utilization in the subsequent process; and massive garbage which is difficult to decompose or incapable of being decomposed is automatically discharged from the unloading port. The organic garbage treatment system with the automatic classification function, which is provided by the invention, has the advantages that the occupied space is less, the garbage treatment energy consumption is low, the system is simple to operate, the running cost is low, the generated odour is less, useful parts in the garbage can be effectively recycled, environment cannot be polluted, and the like. The organic garbage treatment system with the automatic classification function can be used as a front-end pre-treatment classification system in a process for treating garbage rich in organic matters, such as kitchen garbage, and can also be used for carrying out automatic garbage classification treatment in a municipal domestic garbage transfer station.