The invention relates to a LED street lamp device, belonging to the field of lighting equipment. The road lighting is one of the important constituent parts of city infrastructure. With the increasing of perception of environmental protection, environmentally friendly lighting fixtures will be a hop topic. The invention provides a LED street lamp device capable of forming rectangular light spot. In the device, the LED modules 1-50 are arranged in the lighting fixture in group; the optical device is composed of an aspheric central collimating lens, a parabolic reflecting cup and an aspheric microlens array; and the LED light source is arranged at the bottom of the reflecting cup, and the aspheric microlens array is disposed perpendicular to the optical axis. Adjusting the position of aspheric central collimating lens and aspheric microlens array in the parabolic reflecting cup and the elevation angle of LED to make the light from LED parallelly emitted, and finally a rectangular light spot with uniform illumination intensity is formed on an objective illumination surface.