As a typical aerial robot, quadrotor has major advantages when used for aerial photography, environmental monitoring and surveillance in dangerous and complex environments. The robust control problem in attitude tracking of an unmanned aerial vehicle quadrotor is a challenging task due to strong parametric uncertainties, large nonlinearities, and high couplings in flight dynamics. Towards the attitude control of a quadrotor aircraft under lumped disturbances, a fastcontinuous nonsingular terminal sliding mode controller based on linear extended state observer was proposed. In this control structure, a linear extended state observer was used to estimate, and compensate the lumped disturbances, which can enhance the stability of the controller. With its finite time convergence characteristic the nonsingular terminal sliding mode was employed to design the control law, which can increase the convergence speed. Stability of the controller was proved through Lyapunov function. To enhance the control performance, a salp swarm algorithm was introduced to adjust the control parameters of the proposed controller. Furthermore, a 1dimension positive cloud model and an adaptive operator were applied to overcome the defects of the salp swarm algorithm. Lastly, some simulation and experiments were conducted to test the efficiency and application of the controller. The results showed that the proposed controller had higher tracking accuracy, stronger antidisturbance ability and faster response speed.