The photovoltaic microgrid has complex characteristics such as multivariable and strong coupling. To solve the problem that traditional controllers are difficult to achieve ideal control effect, this paper introduces the improved second-order linear active disturbance rejection control technology to the control of the interface converter at the load end of the microgrid. Firstly, the plant is analyzed and the model information is extracted according to the state-space average method. Based on the traditional linear active disturbance rejection controller, the correction function and filter function are introduced to solve the problem of noise sensitivity measurement while the traditional linear active disturbance rejection control(TLADRC) is enhanced with disturbance rejection. On the premise of ensuring the stability of the system, the improved structure is used to improve the anti-disturbance and anti-noise of the system. Finally, the control strategy proposed in this paper and the voltage waveform of DC bus side under linear active disturbance rejection control are compared by simulation under different working conditions, which shows that the active disturbance rejection control strategy proposed in this paper has better control performance.