The invention provides a droop control method and system for a micro-source inverter of a micro-grid. The system comprises a power calculation module, a droop characteristic control module, a reference voltage synthesis module configured to synthesize an obtained frequency and a voltage amplitude instruction value into a three-phase voltage instruction, and a voltage and current double-closed-loopcontrol module configured to select a filter capacitor feedback current of the micro-source inverter as a control quantity of an inner-loop controller, decouple a d axis and a q axis, add cross compensation of the current into a control vector, introduce a bus voltage as a voltage feed-forward, decouple a d-axis bus voltage and a q-axis bus voltage, control the decoupled voltages by adopting a PIcontroller, carry out Park inverse transformation on variables obtained through double-closed-loop control on the current and the voltage to obtain corresponding control signals and control the action of a switching tube of the micro-source inverter. A power component with gentle fluctuation is compensated for a storage battery with high energy density, and stable voltage and frequency are provided for the system.