In order to improve power supply reliability and continuity of traction network effectively, for the lack of relay protection system in traction substation of the existing high-speed railway, a scheme of measure and control system for state of all-parallel AT traction network is proposed. Through expounding its basic principles and system structure, using fault current symbol value, the methods judging the failure of traction network occurring various types of short-circuit are given, combined with power supply of traction network segmentation, a Matlab/Simulink simulation model is built and analyzed for an practical engineering example. The results show that the model can realize the fault removal and service restoration, reduce the range of power failure and reach the purpose of improving power supply reliability of traction network, which verify the correctness and effectiveness of the scheme.