A grinding apparatus includes a base, a case, a transmission module, an inlet water module and drain module. The case is positioned on the base. The transmission module is positioned on the base, and includes a motor and a grinding plate. The motor drives the grinding plate to rotate. The inlet water module is configured for feeding water onto the grinding plates. The drain module includes a drain pan and a drain pipe. The drain pan is detachably attached to the case, the drain pipe is connected to the drain pan, and is exposed from the case.