A photo-timer module, including a upper cover which has a hollow window; a lower cover which could affix to said upper cover; a control and power circuit which is placed into said upper cover, wherein a portion of said control and power circuit is revealed in said hollow window, said control and power circuit has a plurality of input pins and a plurality of output pins wherein the plurality of input pins and the plurality of output pins are stretching out of said lower cover; a mask plate placing above said hollow window comprises at lease one hole thereon, so that a portion of said control and power circuit is revealed in said hollow window, and a transparent plate placing above said mask plate is used for protecting and convenient observing said control and power circuit. After assembly, said control and power circuit could control a power on or off by sensing variation of a light and show the status on said hollow window.