Independent microgrids need to increase secondary frequency control in order to maintain constant frequency. However the conventional secondary frequency control has the disadvantages of slow dynamic characteristics and communication. Therefore, a quasi-secondary control strategy is proposed in this paper. This method does not strictly distinguish the droop control and the secondary frequency control, and adjusts the droop coefficient adaptively by the recursive least squares method to speed up the system frequency recovery without communication. The simulation system was established with a real microgrid in Hainan as a prototype. The comparison results verified the effectiveness of the proposed method.