This article addresses the problem of connected and automated vehicles platoon control under communication interrupted caused by complex and variable environmental factors. A distributed longitudinal vehicle platoon controller based on a combined spacing policy is proposed. Firstly, a combination of the fixed constant spacing policy, the constant time headway policy and the variable time headway policy is embedded to cope with the special cases of communication interruption caused by the leader or follower vehicle, and a new communication topology is established after platoon communication interruption. Then, a novel vehicle platoon controller is developed based on a third-order nonlinear dynamic vehicle model, considering the acceleration error between adjacent vehicles and the combined spacing policy. The asymptotic stability condition of the vehicle platoon is derived using the Lyapunov-Krasovskii theorem. At the same time, serial stability is proven using the infinity norm method. Finally, the effectiveness and stability of the controller are verified through numerical simulations using Matlab and joint simulations using Simulink&PreScan. The simulation results show that the vehicle platoon based on the combined spacing policy can meet different spacing requirements for different scenarios.