A resource allocation method for coexistence of multiple line topological industrial wireless networks is provided. It pertains to the coexistence problem of multiple TDMA-based line topological industrial wireless networks, including three parts: lower bound analysis of scheduling delay, allocation algorithm of inter-network resources and allocation algorithm of intra-network resources. The method uses overall scheduling delay and resource utilization ratio as measurement indexes when analyzing the lower bound of delay and designing resource allocation algorithms, and selects a best node combination in each time slot to occupy as many channel resources as possible to improve the resource utilization ratio and reduce the overall scheduling delay.