Abstract: Neutral beam has potential applications in space debris cleanup and space exploration. As that neutral beam prepared by ion source is not ideal in practice, this paper simulates the long-range transmission effect of non-ideal hydrogen beam in vacuum environment. According to the degree of neutralization, non-ideal beams are divided into under-neutral beams and over-neutral beams. The effects of beam density, neutralization factor, spatial magnetic field and elastic scattering on the nonideal hydrogen beam are studied by establishing a quasi-electromagnetic model of beam transmission. The results show that the presence of negative hydrogen ions has no effect on the transmission of hydrogen atoms in the under-neutral beam, thus the bias magnetic field can be removed to reduce the volume and mass of the device. For the over-neutral beam, the loss ratio is related to the beam density and neutralization factor, that is, the higher the beam density, the greater the beam loss; the higher the neutralization factor, the higher the beam loss. The magnetic field and the elastic scattering between particles have no effect on the propagation of either the under-neutral or over-neutral beams.