The invention provides a horizontal-well-oriented drilling layer ranging radar device, aiming to maintain wellhole tracks at an optimum location. The drilling layer ranging radar is divided into two frequency ranges to perform deep detections and shallow detections with high resolution simultaneously at the upper and lower directions of a level guide drilling tool. Detecting depth of electromagnetic wave can reach 10 meters at the frequency range of 50m-900m, while the detecting depth of the electromagnetic wave can reach 0.5 meters at the frequency range of 1G-5G. The level guide drilling tools are guaranteed not to be out of coal beds, hydrocarbon layers or other ore storage layers during during the process of level drilling.