The ubiquitous matching and non-matching disturbances in aircraft all-electric braking systems will reduce the slip rate and braking pressure tracking accuracy, and it is difficult to achieve high performance control of aircraft all-electric braking systems. An improved sliding mode composite control method based on cascade expansion state observers and finite-time prescribed performance inversion is proposed for the aircraft all-electric braking systems. Firstly, an optimized mathematical model of the aircraft all-electric braking systems is established considering matching and non-matching disturbances, and a cascade extended state observer is designed to estimate non-matching and matching disturbances in real-time. Secondly, a sliding mode control method is designed based on disturbance estimation and finite time preset performance inversion, so that the slip rate can accurately track the expected value within the preset-time. Thirdly, an improved non-singular global terminal sliding mode control method is designed based on disturbance estimation. The braking pressure can accurately track the reference virtual braking pressure, allowing the aircraft all-electric braking systems to obtain the maximum braking pressure quickly and improve braking performance. Through the comparative simulation analysis in different runway states, it is verified that the aircraft braking composite control method proposed can improve braking efficiency.