In this study, a CFD model was developed to simulate syngas production from microwave-assisted air gasification of biomass. The energy source term under microwave irradiation was coupled in the model to describe the effect of microwave power and the gasification model was established by Euler-Euler method in commercial software Ansys Fluent. Both gas and solid phases were treated as continuous phases, and they have independent governing equations. The two-fluid model was used to describe the two-phase flow and interaction, and the standard k-epsilon model was used to close the governing equations. The heterogeneous reaction rate between gas and solid and the homogeneous reaction rate between gases were calculated by the finite rate/eddy dissipation model. The fast and transient control characteristics of microwave heating were loaded into the gasification reaction model through UDF compiling function. (C) 2019 Elsevier Ltd. All rights reserved.