Abstract: To investigate the feasibility of the air-breathing helicon plasma thruster, such a thruster is numerically simulated based on the propellant in the 180 km ultra-low orbit, with consideration of the collision, the excitation and the ionization processes. The propellant, composed mostly of atom oxygen, is absorbed and heated by the electromagnetic wave with a radio frequency of 13.56 MHz, and eventually ejected from the magnetic nozzle. A structure model of the air-breathing helicon plasma thruster is established. The deposited power, the distributed plasma parameters and the thrust output are calculated for various input powers. It is shown that with the input power increased from 200 W to 2000 W, the thrust increases from 6.00 mN to 13.23 mN, enough to compensate the atmospheric resistance. The result can be used in the design of this kind of thrusters.