Abstract: To calculate the reliability of gas gathering stations, the topological structures of process systems at gas gathering stations were analyzed and the connection relation between their units was investigated. L-13 gas gathering station was taken as the example, its topological graph of the main process system was built based on the graph theory. Then, the fully connected matrix and the connection series of each node before and after the outage of water jacket furnace at this station were calculated by using the initial adjacency matrix squaring method which belongs to the matrix analysis method, combined with the MATLAB software. It is indicated that the process system of this station belongs to the same connection area before and after the outage of the water jacket furnace, and there is no independent unit in this system, so it is necessary to take into consideration the interactions between the units when the reliability of the system is calculated. The interaction between two adjacent nodes is the greatest. The interaction between node 6 and node 7 is the smallest before the outage of the water jacket furnace, and that between node 1 and node 7 is the smallest after the outage. The variation of the connection series between nodes is in line with the actual technological process. It is demonstrated that the graph theory and the matrix analytical method can meet the requirements of dynamic topological analysis on the process system of stations.