SIDO Buck变换器在受到负载扰动时，支路间存在严重交叉耦合影响，同时，输出信号易受到高频测量噪声等不确定因素影响。针对上述问题，提出了一种基于高阶滤波超螺旋扩张状态观测器的滑模自抗扰控制策略。首先，根据SIDO Buck变换器的数学模型，将内部参数影响和外部扰动等不确定因素分离为集总扰动，建立不考虑物理参数的自抗扰模型；其次，设计了一种高阶滤波超螺旋扩张状态观测器，实现对集总扰动更加精准地估计补偿，提高抑制噪声和交叉影响的能力，并根据有限时间稳定性理论证明其稳定性；然后，设计了改进的超螺旋滑模反馈控制律，保证滑动模态阶段和到达阶段能快速收敛，同时更好地抑制抖振。并通过选取Lyapunov函数对反馈控制律进行稳定性分析；最后，利用仿真和实验，对比验证了所提控制策略的优越性，有效地减小了交叉影响，抑制了噪声，提高了系统的暂态性能。

When the SIDO Buck converter is disturbed by the load, there is a serious cross-coupling between the branches. At the same time, the output signal is susceptible to uncertain factors such as high-frequency measurement noise. Aiming at the above problems, an improved sliding mode active disturbance rejection control strategy based on high-order filtering super-twisting extended state observer is proposed. Firstly, according to the mathematical model of SIDO Buck converter, the uncertain factors such as internal parameter influence and external disturbance are separated into lumped disturbance, and the auto -disturbance rejection model without considering physical parameters is established. Secondly, a high-order filtering super-twisting extended state observer is designed to achieve more accurate estimation and compensation of lumped disturbances, improve the ability to suppress noise and cross-effects, and prove its stability according to finite-time stability theory. Then, an improved super-twisting sliding mode feedback control law is designed to ensure that the sliding mode phase and the arrival phase can converge quickly, and the chattering is better suppressed. The stability of the feedback control law is analyzed by selecting the Lyapunov function. Finally, the superiority of the proposed control strategy is verified by simulation and experiment, which effectively reduces the cross influence, suppresses the noise and improves the transient performance of the system.