The invention relates to a near-infrared laser ranging method based on a linear sensitive photon detector, and belongs to laser ranging and weak infrared light detecting types. A ranging system achieves the linear sensitive photon detection on the basis of the external gain based on the pulse laser flight time ranging method and through the combination of a PIN photodiode and an EDFA, echo light with different intensities can be detected, accordingly, the distance information is obtained, meanwhile, the materials of a detected target is judged according to the specific number of returned photons, and precise measurement of different distances and different targets is achieved. Compared with other sensitive photon detection, the horizontal return light linear detection from a single photon to multiple photons can be achieved by adjusting the gain multiple of the EDFA, the photon number can be detected in a distinguishable mode, the working range of the laser ranging is greatly enlarged, the near-infrared laser ranging method meets the requirements for near, medium and remote laser ranging at the same time, and the fast distinguishing of the detected target material is achieved.