With the flexible multi-body dynamics theory, the dynamic characteristics of the arm system of folding-boom aerial platform vehicle (FBAPV) were analyzed. The flexible multi-body dynamics equation of the arm system of FBAPV was established by with flexible multi-body dynamics theory and the Lagrange equations. Through the derivation and numerical solving of differential equation, the rigid and the flexible model were respectively given. Comparison of simulation results of both two models, the results indicate that considering the implications of each arm rods flexible deformation is necessary. Research results for FBAPV trajectory precision and oscillation control of table will have an effective reference.