This paper designs a biomass gasification cyclone burner and analyzes the effects of the gasphase isothermal flow field of the biomass gasification cyclone with different inlet structures and different inlet section angles using the Fluent software. The distribution of tangential velocity and axial velocity are obtained. Results show that the form of double symmetrical inlets improves axial symmetry of the gas-phase isothermal flow field of the biomass gasification cyclone; the inlets with oblique angles change the position of gas into the cyclone, which greatly reduces the internal local vortex; short circuit flow is very small with 25°. When the entry angle is 25°, tangential velocity reaches maximum; when the tilt angel is 45°, axial velocity reaches maximum. The results of this study will provide a foundation for the development and application of biomass gasification cyclones.