Low-altitude flight vehicles operating in urban airspace face severe challenges from complex wind disturbances and model uncertainties, which significantly degrade trajectory tracking accuracy and flight safety. Aiming at the trajectory tracking problem of unmanned aerial vehicles in low-altitude urban environments, this paper analyzes the disturbance characteristics of urban wind fields and establishes a nonlinear dynamic model of a multirotor aircraft. Based on this, a composite control strategy combining an Extended State Observer and adaptive robust control is proposed. The Extended State Observer estimates and compensates for lumped disturbances including wind gusts and parameter perturbations in real time, while the adaptive law adjusts control parameters to cope with inertial uncertainties. Simulation results demonstrate that, compared with traditional PID control, the proposed method reduces the root-mean-square trajectory tracking error by more than 58% under wind disturbance conditions and shortens the settling time by approximately 35%, while maintaining bounded control outputs suitable for embedded implementation.