Aiming at the problem that the DC bus voltage measurement link of grid-connected inverter in wind power system is easy to be polluted by noise, a linear active disturbance rejection control (LADRC) and filter are combined in this paper to construct an improved linear active disturbance rejection control technology based on filter function. The mathematical model of wind power grid-connected inverter is constructed, and the traditional LADRC is analyzed. In order to improve the suppression of high frequency noise by active disturbance rejection control, the filtered voltage is expanded into a new state variable, and the filtered voltage is estimated by using the linear extended state observer and the voltage value is used as feedback. On the premise of considering that the system output contains noise, the frequency domain characteristics of the improved LADRC are analyzed. The results illustrate that the improved control strategy has better noise suppression capability. The feasibility and effectiveness of the proposed control strategy are verified by the establishment of a simulation platform for grid-connected inverter of wind power system.