Abstract: The attitude system of vertical take-off and landing multi-rotor unmanned aerial vehicle(UAV) is characterized by high nonlinear and strong coupling. And the external disturbance and internal uncertainty in the system will affect the flight quality of the UAV. In order to improve the stability and robustness of the UAV attitude control, the attitude system of multi-rotor UAV with coexisting external disturbance and internal uncertainty is established, and an adaptive attitude control method based on the improved double closed-loop integral sliding mode is proposed in this paper. Through simulation verification, the proposed system can perform the attitude control task effectively and steadily, which possesses certain anti-interference ability. The method proposed in this paper can provide certain reference value for the development of UAV control technology.