Multi rotor unmanned aerial vehicles (UAVs) face challenges in aeromagnetic detection, including magnetic field interference, wind field changes, and mechanical vibrations. These interferences lead to UAV attitude deviation, unstable trajectories, and data distortion. In order to ensure the safe flight of multi rotor unmanned aerial vehicles during aeromagnetic detection, an adaptive stable flight control method for multi rotor unmanned aerial vehicles under aeromagnetic detection is proposed. Considering the composition structure and working principle of multi rotor unmanned aerial vehicles, simulate the stable flight process of multi rotor unmanned aerial vehicles under aeromagnetic detection, and obtain the flight pose of the unmanned aerial vehicle. Calculate the flight pose of a multi rotor unmanned aerial vehicle as the initial data for the control method. Detecting the interference state of unmanned aerial vehicles from three aspects: magnetic field, wind field, and mechanical vibration. Based on the calculated flight control variables, the multi rotor unmanned aerial vehicle achieves adaptive stable flight control through interference compensation, vibration suppression, and pose adaptive control. The experimental results show that under single and composite interference environments, the flight stability coefficient of multi rotor unmanned aerial vehicles using optimized design control algorithms is significantly increased, and the magnetic intensity detection error is reduced by about 2.9 milliGauss.