Regional computer interlocking equipment is the core equipment to ensure the safety of regional traffic and transport efficiency, and the reliability research of it is of great significance. Combining the two existing regional interlocking schemes, a new interlocking scheme is proposed, that is, both the main control station and the slave control station (choose one or more stations) are equipped with interlocking equipment. Taking the common cause fault and maintainability of interlocking system into account, the dynamic Bayesian network is used to analyze the reliability. Firstly, from the perspective of system fault-safety and dangerous output, the dynamic fault tree of two interlocking units and triple interlocking units are established and then it is transformed into the corresponding dynamic Bayesian network models. By using the reasoning characteristic of dynamic Bayesian network, the reliability of regional interlocking equipment is analyzed. Finally, the results of this method are compared with those of static Bayesian network and dynamic fault tree analysis. The results show that it's the best way to set up interlocking equipment in the main control station and one of the slave control stations and the reliability analysis based on dynamic Bayesian network has obvious advantages over the above two methods in terms of calculation accuracy and time complexity. Through the diagnosis and reasoning of dynamic Bayesian network, it is known that common cause fault is the main cause of system fault, so we should focus on prevention of it to reduce the probability of accidents.