In order to solve the problem of service blocking caused by Inter Core Crosstalk (ICXT) in Space Division Multiplexing Elastic Optical Network (SDM-EONs), a dynamic routing and crosstalk sensing algorithm is proposed. Firstly, in the routing stage, a candidate path sorting formula combining the shortest path and path loading is designed to dynamically select a more appropriate path for business requests according to the system load. For the problem of inter core crosstalk in multi-core fiber, a crosstalk sensing strategy is proposed to minimize the impact of inter core crosstalk, with improvement of the probability of successful transmission and reduction of the blocking rate. In order to evaluate the performance of this algorithm, the ICXT improvement index is defined to evaluate the performance difference between this algorithm and the comparison algorithm. Simulation results show that the algorithm in this paper has a significant improvement in blocking rate performance and inter core crosstalk compared with many comparative literatures.