A switch module of a photoelectric integrated mechanical shaft keyboard, having a casing and a key cap a driving device, a photoelectric switch, a movable optical module and a fixed optical module. The photoelectric switch has a PCB, an SMD IR integrated on the PCB and an SMD PT tube. By pressing down the key cap, the driving device drives the movable optical module to move up and down to control the relative positions of the movable optical module and the fixed optical module. When light emitted by the SMD IR tube is coupled into the SMD PT tube, an optical path is connected, so that the photoelectric switch is turned on; and when the light emitted by the SMD IR tube cannot be coupled into the SMD PT tube, the optical path is disconnected, so that the photoelectric switch is turned off.