The utility model belongs to marking device field, concretely relates to portable construction safety hidden danger fast marking device, including the casing, the inside fixedly connected with the box of casing, the inside of box is connected with the cover through
screw thread, the cover is contacted with casing, the inside fixedly connected with the connecting block of casing, the connecting block is contacted with box, the inside of casing is contacted with the marking cotton, the marking cotton is fixedly connected with the connecting block. The utility model discloses through design fixed block, fixed plate, sliding block, screw rod,
handle and sliding slot etc. component, removes screw rod from sliding block, then personnel will hand move to fixed plate, removes sliding block, clamping plate and clamping
sponge etc. component, and clamping
sponge moves and contacts personnel hand, then installs screw rod into sliding block, and then makes clamping
sponge etc. component get the limit, and then makes personnel hand get clamping, makes the device convenient to carry.