In order to test the key technologies of long-range LADAR, the experimental system was proposed based on the Nd:YAG laser. The system was combined with optical sub-system, control sub-system and signal process sub-system, and directed by charge-coupled device(CCD) when working. Coarse and fine dual-axis structure was adopted to realize the precise tracking of the target. Meanwhile, in order to increase the detection precision, the laser signal was processed in digital domain. At last, the detection range of the system was analyzed versus different laser cross section targets(LCS). The result shows that if the LCS is 1 m2 and the atmosphere is first order, the detection range of the system is 22 km.