In the virtual network functions service chain(VNF-SC), When a user applies for a service request and the network operator allocates spectrum and Internet technology(IT) resources for the request, due to the different service requests and resource release times, the spectrum resource utilization is often low, spectrum fragments are generated, and subsequent VNF-SC requests are blocked. A joint multi segment path algorithm for optimizing VNF-SC deployment in elastic optical network (IDC EON) between data centers is proposed. The algorithm divides each end-to-end path into multiple path segments with the data center as the boundary, and considers the impact of spectrum resource overhead and utilization on each path segment, selects the end-to-end path with the smallest objective function value to deploy the VNF-SC. The simulation results show that the proposed algorithm has a lower blocking probability than existing algorithms.