A ground-based multisensory fusion approach was proposed for the guidance of UAVs (unmanned aerial vehicles) landing in GNSS (global navigation satellite system) denied environments. Firstly, an active laser transmitter was used to irradiate the UAV. The light spot in the obtained infrared images reflected by the airborne reflection prism was recognized as the UAV. Then, a region of interest was defined in the visible-light image by coordinate transformation according to the result of the infrared image. To reduce the computation complexity, the UAV was detected and located in the region of interest. Finally, the relative position of the UAV can be obtained by combining the distance measurement and the angle of the pan-tilt unit. Results of flight experiments demonstrate that the proposed approach can offer the precise positional information of UAV and can effectively adapt the complex background of UAV autonomous landing.