The invention relates to a roadway detection stroboscopic illumination device which is provided with a lamp hanger bottom plate connected on a butt plate at the rear end of a detection vehicle by regulating hinged support pieces at the upper part and the lower part; an inclined lamp hanger is installed on the lamp hanger bottom plate, two paraboloid trough type reflecting shades are closely arranged side by side along the slant direction in the lamp hanger, and one or a plurality of flash lighting tube(s) which can project and illuminate towards the slantingly downward direction is/are arranged on the top of the internal groove surface in the two reflecting shades. When the stroboscopic illumination device is in use, after an electric control system starts, the flash lighting tube(s) in the lamp hanger can emit direct light, and the light reflected by the reflecting shades irradiates on the object plane, so that a lighting surface with high brightness is formed. Furthermore, the inclination angle as well as the upper and lower positions of a lamp body can be regulated by the regulating hinged support pieces at the upper part and the lower part, and the device can meet the requirements of illumination with different brightness by the control of a control circuit, thus adapting to the requirements of the installation structure of different illuminating systems in the roadway detection.