Circulating　current　suppression　can　effectively　improve　the　reliability　and　redundancy　of　parallel　inverter　systems.　The　mechanism　and　influencing　factors　of　the　low-　and　high-frequency　zero-sequence　circulating　current　(ZSCC)　are　analyzed　in　this　study.　Based　on　a　mechanism　analysis　and　the　built　mathematical　model,　the　composite　control　strategy　of　zero-sequence　voltage　difference　(ZSVD)　compensation　and　virtual　inductance　is　proposed　to　suppress　the　low-　and　high-frequency　ZSCC.　In　the　composite　control　strategy,　the　low-frequency　ZCSS　(LF-ZCSS)　is　suppressed　by　the　ZSVD　compensation　method,　and　the　HF-ZCSS　is　suppressed　by　the　virtual　inductance　method.　The　ZSVD　compensation　is　incorporated　into　the　SVPWM　as　an　input　to　regulate　the　modulation　and　suppress　the　LF-ZCSS,　and　virtual　inductance　is　introduced　into　the　current　control　loop　to　suppress　the　HF-ZCSS.　A　parallel　system　prototype　composed　of　two　6　kW　inverters　is　constructed.　The　experiments　show　that　the　ZSCC　of　the　parallel　system　is　reduced　by　45%,　which　verifies　the　effectiveness　of　the　proposed　composite　control　strategy.