The invention discloses a kitchen waste disposal system. The kitchen waste disposal system comprises a waste grinding machine, an electric control valve and a control box; the waste grinding machine is provided with a top opening in butted connection with a water tank drain hole and a side opening in butted connection with a drainage pipeline; the electric control valve is in series connection with a water supplying pipeline of a water tank; and the control box starts the waste grinding machine and opens the electric control valve in response to a system starting signal, and the control box shuts down the waste grinding machine and closes the electric control valve in response to the clearing task completing state of the waste grinding machine. Based on the kitchen waste disposal system, starting and stopping of the waste grinding machine and a water source of the water tank can be controlled synchronously by the control box, and thus manual operation and control of a user can be simplified.