To provide a rubbish-grinding-and-sorting system which improves a rubbish-recovering rate when grinding and sorting processing is made.

The rubbish-grinding-and-sorting system 200 is provided with an accommodation hopper 2, which accommodates waste materials which include foreign matters, and a grinding and sorting machine 5 which grinds and separates the foreign matter from the garbage 1 accommodated in the accommodation hopper 2. In this case, the system is provided with; a residue-separating device 14, which separates a residue from the foreign matter separated by the grinding and sorting machine 5; a residue reception box, which accommodates the residue discharged from the residue-separating device 14; a residue-discharging pipe conveyor, which conveys the residue discharged from the residue-separating device 14 to a residue box 18; a branch 20, which is provided halfway in the residue-discharging pipe conveyor 16; and a residue-returning pipe conveyor 17, as a returning system, which is connected to the branch and returns at least a part of the residue discharged from the residue-separating device 14 to the accommodation hopper 2.