Abstract: The 3D model of plant based on 3D laser scanning technology can reflect plant morphological characteristics accurately and comprehensively without artificial disturbance. It has obvious advantages over the traditional measure- ment method. Maize grown under low phosphorus conditions (20 mg / kg). The inoculation ( Glomus intraradices) treatment and blank control treatment were established. A 3D laser scanning technology was used for dynamic monito- ring on the maize morphology in different growth times. Considering the infection rate,hyphal density,acid phosphatase activity,available phosphorus and other physicochemical indexes,the change law of the effect of arbuscular mycorrhizal fungi on the growth of maize was summarized. The results show that under low phosphorus conditions,the infection rate reaches 82% in 30 days,and the hyphal density and the acid phosphatase activity also increase. When the maize grows for 30 days,the plant height and crown width in the inoculation group increase by 52% and 47% respectively com- pared with that in the control group. While in 60 days,the cross-sectional area of stem in the inoculation group is 124% of that in the control group. Moreover,the leaf area,leaf width and the vertical height of the blade and so on all increase,and the difference between inoculation treatment and CK treatment is increased with time increase. Radius of curvature was used to express the leaf bending degree. When the corn grows for 60 days,the curvature radius in the in- oculation group increases by 46． 5% compared with that in the control group,which indicates that the arbuscular my- corrhizal fungi can strengthen the leaf.