A solution of optical system to receive laser echo light based on the configuration and transmission properties of fiber bundle is proposed. This system just needs a detector with diameter of 3 mm for realizing the panoramic detection. The system consists of three parts: front coupling system, fiber bundle and rear focusing optical system. 8 sets of coupling subsystem couple the eight sectors′ laser echo lights into the fiber bundle. Then, fiber bundle as a device to collect light, converts the 8 rectangular fields of incident light into a circular field of emergent light matching the circular detector. The emergent light from the fiber bundle is converged on the detector by the rear focusing optical system. The energy receiving efficiency is more than 80% and the difference between each view is less than 8% through simulation. The result indicates that the system′s detection range is far and consistent in each direction. Due to requiring only one infrared detector to realize no blind spot panoramic detection. It facilitates subsequent processing.