To investigate the influence of flexible cables on mechanical properties and stability of space cablestrut deployable articulated mast,the minimum design value of the cable prestress which satisfies the mast bearing structure requirement has been calculated based on the self-balance mechanics analysis of mast.Results indicate that the driving moment increases with the linearly increased cable prestress.The axial stiffness,shearing stiffness and tortional stiffness of mast increase with the increasing axial extensional stiffness of cable.Statics experiments indicate that the cable prestress has nearly no influence on the static stiffness of mast.Simulation analysis show that increasing the cable diameter can enhance the tortional vibration frequency of mast sufficiently,while the cable prestress and cable diameter have little influence on bending vibration frequency and axial vibration frequency.Dynamics tests on the mast truss bays with different cable prestresses have verified the correctness of simulation.The structural mechanics analysis of mast joint show that increasing the cable prestress is advantageous to the improvement of mast stability.