A safety food grinder is applied to grind food and has a base, a container assembly, multiple movable stops and a cover. The base has a driver. The container assembly is mounted detachably on the base and has a cutting tool and multiple sliding channels. The cutting tool is connected detachably to and is selectively driven by the driver. The movable stops are respectively mounted slidably in the sliding channels and selectively keep the cutting tool from being driven by the driver. The cover is detachably mounted around the container assembly and selectively moves the movable stops to allow the cutting tool to be driven by the driver. Consequently, the cutting tool is only driven when the cover is mounted on the container assembly and the base so prevents users from being cut accidentally even when the safety food grinder is turned on unexpectedly.