This paper investigates the consensus problem of the frequency, voltage and energy level for heterogeneous battery energy storage systems in an islanded microgrid. Considering the primary droop control, a new distributed finite-time secondary control strategy is proposed. The proposed control scheme is implemented to restore the frequency and voltage to the rated values, and achieve the energy level balancing and active power sharing within a finite-time. The advantage of this control method is that the upper bound of settling time is independent of any initial conditions, which guarantees the timeliness of finite-time control of the microgrid. The consensus convergence characteristics of the proposed control strategy are analyzed based on the Lyapunov method. Finally, simulation results with Matlab/Simulink demonstrate the effectiveness of the proposed distributed finite-time secondary control strategy.