The new aircraft is facing the development needs of integration and intelligence, and the actuator, as the actuator for aircraft actions, is worthy of in-depth study of its integrated displacement perception method and signal stability under working conditions. Taking a certain type of landing gear steering mechanism actuator as the research object, aiming at the phenomenon of zero point and amplitude drift of the existing capacitive integrated displacement sensor under oil conditions, this paper proposes to use the drag increase and deceleration effect of the surface microstructure to homogenize the oil film and abrasive debris between the capacitive plates. The finite element simulation technology was used to design and optimize the form and parameters of the microstructure, the ultra-precision machining technology was used to process the microstructure on the surface of the plane sample and the actuator shaft, the tribological properties of the microstructure with different parameters were tested by the UMT friction and wear testing machine, and the capacitance signal change law before and after the processing of the microstructure on the surface of the actuator shaft was compared by the self-made capacitance signal detection platform. The results show that the resistance increase and deceleration efficiency of the surface microstructure can achieve the homogenization of the oil film between the capacitor plates, and then ensure the stability of the capacitive signal under the oil condition, thus the research results can promote the engineering application of the integrated displacement sensing actuator.