In low voltage microgrid, the transmission line is relatively resistive and that is the reason why power coupling problem will be caused when conventional droop control method is adopted. Virtual power droop control method based on coordinate transformation could realize power decoupling control. Aiming at the problem that the frequency and voltage quality of the microgrid in islanding operation cannot be guaranteed by the fixed virtual power droop coefficient, a new virtual power droop control strategy based on Lagrange interpolation is proposed, which could guarantee the frequency and voltage quality while the output power of the inverter is within its allowable range. The robust power allocation method is adopted to achieve reasonable power allocation of parallel inverters, which makes the virtual power distribution not be affected by the line impedance. A parallel model of two inverters with different line impedances using the above strategy and the fixed droop coefficient strategy are simulated respectively. Simulation results indicate that the new droop control method could guarantee good power quality and reasonable power allocation between parallel micro-sources. This work is supported by National High-tech R & D Program of China (863 Program) (No. 2015AA050603).