Due to the low redundancy of the traditional beam string structure, it is easy to cause a continuous collapse of a structure when the lower string prestay cable is broken by accident. A new type of beam string structure is proposed by improving the traditional tensioned beam spars, lower chords and the connection forms among members. Based on ANSYS/LS-DYNA program platform, some new beam string structure models with different spars crossover angles and spars numbers are analyzed for continuous collapse resistance by using the instantaneous unloading method of the equivalent load in the initial state. The results show that after reasonable design, the cross strut will replace the lower chord at the failure to provide a spare force transmission path for the structure when any section of the lower chord fails，and the new beam string structure will not progressive collapse, but the lower spar internal force will increase suddenly, the large bearing allowance shall be reserved for the design of the lower brace. And also show that the closer the brace cross node is to the bottom chord, the more obvious the effect of the vierendeel truss of the remaining structure and the better the load carrying capacity. The more cross brace groups, the higher the structural redundancy, and the better the progressive collapse resistance of the new beam string structure.