Based on the measurement principle of multi-baseline digital close-range photogrammetry system,this paper proposed method of gain forest measurement factors by this system. Through comparing research of the statistical results in photogrammetry data of stumpage and measured data of total station,the result indicates that people may gain more reliable data by multi-baseline digital close-range photogrammetry system,accurately monitor forest and meet the need of forest measurement by this system. At the same time,by establishing three-dimension point cloud model based on 3-D model of tree,people may expediently gain forest measurement factors which shall be harder by traditional methods.