Abstract: The micro radio frequency(RF) ion thruster is one of the international research hotspots in the field of micro-electric propulsion because of its simple structure, long lifetime, large thrust range and quick response. The performance of RF ion thruster is closely related to the characteristics of plasma in discharge chamber. To this end, a fluid model of inductively coupled plasma in micro RF ion thruster with low pressure and small size was established. A multi-physical coupling simulation involving electromagnetic field, flow field and chemical reaction concentration field was carried out. The variations of characteristic parameters of plasma with propellant pressure, absorption power, RF frequency and coil turns were studied. The results show that the propellant pressure and the absorption power are the main factors to regulate the performance of micro RF ion thruster. This study lays a good foundation for comprehensively regulating the performance of micro RF ion thruster.