A projector protection method includes: multiple temperature sensors detect temperatures of multiple areas in a projector to obtain multiple temperature parameters respectively; a processor lowers an output power of a laser source when any temperature parameter corresponding to one of areas falls into corresponding one of multiple first temperature intervals and multiple fans in the projector are set to a maximum speed; and the processor turns off the laser source when any temperature parameter corresponding to one of areas falls into corresponding one of multiple second temperature intervals. The second temperature interval and the first temperature interval corresponding to the same temperature parameter are different from each other.