In order to improve the safety factor of scientific expedition personnel when detecting unknown environment, realize non-contact measurement, and to solve the problem that two-dimensional planar imaging cannot obtain the distance information and size information of the object, a set of three-dimensional scanning imaging system based on single-point pulsed laser rangefinder is designed and realized. First, variance filtering and Gaussian fitting are used to improve the accuracy of single-point laser ranging. Second, after correcting the angle deviation of the pan-tilt, the point cloud data on the surface of the object can be obtained through the rotation of the pan-tilt. Finally, density-based spatial clustering of applications with noise (DBSCAN) algorithm is used to filter the acquired point cloud noise to obtain a three-dimensional point cloud image with clear outline, clear angle, and accurate distance. Indoor imaging experiments on ordinary paper boxes show that the system distance measurement error, object area size measurement error, and angle fitting error are all within 5%; and outdoor imaging experiments on large buildings within 200 m show that the system can effectively detect unknown environments and perceive obstacles.