Aimed at the problems that current research on the static deployment of software defined satellite network controllers is ignorence of the dynamic topology of satellite networks， and the user data traffic is unsteadly，a multi controller dynamic deployment method based on the modified whale optimization algorithm (MWOA) is proposed in comprehensive utilization of the dynamic characteristics of satellite networks by setting three threshold values and adopting switch migration in combination of the software defined satellite network architecture. The simulation results show that compared with other algorithms, MWOA has significant advantages of switching migration costs, controlling link delay, and load balancing. This method can further improve the processing performance of satellite networks and meet the needs of communication for users.