The invention discloses a rapidly-unfolded LED searchlight for the construction site. The rapidly-unfolded LED searchlight comprises an installing plate. Two fixing blocks are fixedly connected to oneside of the installing plate, and the opposite sides of the two fixing blocks are fixedly connected with rotation rods. The rotation rods are in cup joint with a rotation barrel. One side of the sidesurface of the rotation barrel is fixedly connected with one side of a reflection plate, and one side of the top of the reflection plate is fixedly connected with a connecting block. Through usage ofa movable disc, two hand rods are pulled in the opposite directions, inserting rods disengage from the interiors of inserting holes, accordingly, the movable disc can be moved on a connecting main rod, a pull rope is further pulled to move, and accordingly the reflection plate on the searchlight can be rapidly unfolded; through usage of a fixed disc, the pull rope can rotate on a limiting wheel,accordingly the phenomenon of jamming due to contact of the pull rope and a through port is avoided, and accordingly it is guaranteed that the reflection plate can flexibly rotate; and meanwhile, theservice life of the pull rope is prolonged, and the unfolding time is saved to a certain degree.