The invention discloses a protective device for a moving protective hood of a manual mini saw. The protective device comprises a machine body, a switch, a switch button, an unlocking button, a baseplate, a fixed protective hood and the moving protective hood, wherein the switch, the switch button and the unlocking button are arranged on a handle of the machine body; the fixed protective hood is arranged on the machine body; the baseplate is hinged with the fixed protective hood; a cutting slot matched with a saw blade is arranged on the baseplate; the moving protective hood is hinged with thebaseplate and connected with the fixed protective hood in a sleeving manner; the unlocking button is capable of moving left and right along the handle; a connecting rod is arranged in a shell of the machine body; a limiting slot capable of pushing the connecting rod to move back and forth is arranged on the unlocking button; a limiting lug boss is arranged at the side end of the moving protectivehood; the rear end of the connecting rod is positioned in the limiting slot; the front end of the connecting rod is matched with the limiting lug boss; and a blocking part is arranged at the lower endof the unlocking button, so as to limit the pressing of the switch button and the triggering of the switch. The protective device disclosed by the invention is simple in structure and the occupied size of the unlocking mechanism is small.