In this paper, swarm control for multiple unmanned surface vehicles subject to time-varying environmental disturbances and input saturation based on state feedback controllers is studied. Firstly, to accurately measure the environmental disturbances, a finite-time disturbance observer is proposed. Then, to solve the actuator saturation, an auxiliary dynamic system is introduced. Furthermore, a state feedback controller is designed for each USV to realize the swarm control of multiple unmanned surface vehicles. The stability of the system is proved using the Lyapunov method. The effectiveness of the proposed controller is verified via simulation results.