Bogie is an emblematic complex mechanical as well as electronic part of the current high speed rail system. A small failure of components may lead to a loss of production, casualties and damage of the system. Therefore, security and reliability analysis of bogie system is a predominant task. This paper proposes a stochastic network flow model of bogie system based on the forces applied on the components of the bogie, simultaneously considering the deterioration level and functional correlation of components. At first, a detailed description of structure and functions of the CRH3 bogie is introduced. Then a stochastic network flow model is constructed by analysing the direction of various forces applied on bogie. In the proposed model, edges represent the bogie components and vertices are the transmission channels. The flow over each edge is analysed by the forces it withstands. Finally, a combination method using minimal cut sets is proposed to evaluate the reliability of high speed train bogie system. This paper provides a supportive guidance and practical approach to bogie system designers for efficient operation and maintenance of the bogie.