A simple collapse structure of tool hanger board is provided, especially for reducing package volume of the hanger with a tool inserted therein. The hanger board has a hanger board body that functions to hang a tool for exhibition. The hanger board body has a lower portion that forms an insertion slot for receiving insertion and positioning of a tool therein. With a retention plate projecting from the body for securely looping and fixing the tool, secure insertion of the tool can be realized. An upper portion of the body that is located above a central positioning bar is made as a pivotally connected foldable upper board section. The upper board section is folded downward to overlap a rear surface of the board body so as to reduce the overall length of the hanger and thus effectively reduce the package volume, facilitate handling and lower costs of packaging and shipping.