Satellite Elastic Optical Network (SEON) is an important development direction of satellite Internet with the advantages of large capacity, strong anti-interference ability and flexible resource management and control. The routing and spectrum allocation (RSA) problem is a critical issue in SEON. To solve the RSA problem in SEON, a dynamic routing and spectrum allocation algorithm based on the path state-aware (PIV-SSA) is proposed. The PIV-SSA consists of a segmented spectrum allocation (SSA) algorithm and a path influence value routing selection (PIV) algorithm. In the SSA, the location of the spectrum resources allocated to the services are determined by the transmission rate it requires. In the PIV, the optimal transmission path is selected by comprehensively considering factors such as spectrum resource consumption, link spectrum status, and path survival time based on the pre-allocation results of the SSA algorithm. The results of the simulation experiments show that, compared to the classical KSP-FF algorithm, the PIV-SSA algorithm reduces the network blocking rate by an average of 4.60% and achieves an average improvement of 4.78% in network spectrum utilization under different load intensities.