Abstract: A coupling trajectory tracking controller based on a quasi-steady model is proposed for the trajectory tracking problem of tailless flapping-wing vehicle. Firstly, the aerodynamic characteristics of the vehicle are modeled and analyzed using the quasi-static model and the blade element method, resulting in the construction of a quasi-steady aerodynamic model. Secondly, the attitude of the vehicle is described using quaternions, and a coupled dynamic model of the flapping-wing aerial vehicle is established to comprehensively reflect its motion characteristics. In the controller design phase, an intermediate control variable is introduced, and a model-based dual-loop coupled control scheme for position and attitude is designed based on the undecoupled dynamic model of the vehicle, to achieve high-precision trajectory tracking control. The global stability of the control system is proven through an analysis based on Lyapunov theory. Finally, simulations and actual flight experiments are conducted. The prototype is set to track a spiral ascent trajectory and a V-shaped trajectory. In the simulations, the prototype demonstrates rapid response capability during the tracking process and maintains stable posture. In the actual flight experiments, the prototype completes the tracking of the spiral ascent trajectory and executes the V-shaped trajectory tracking task within 6 s, proving the effectiveness of the designed controller.