In this paper, the physical model of low voltage Direct-current (DC) glow discharge in cross field is established. Based on the magneto-hydrodynamic method (MHD), the mathematical expression of steady-state plasma physical parameters under cross field condition is derived, and the influence of magnetic field on low-pressure glow plasma physical parameters is analyzed. The theoretical results show that the magnetic field can effectively increase the electron density and ion density of plasma at low pressure. The magnetic field can increase the glow discharge current, and the introduction of the magnetic field makes the plasma concentrate to the discharge center. The effects of parallel field and cross field on glow discharge are compared by experiments. The experimental results show that the cross field has more influence on the glow plasma density than the parallel field, and the experimental results are consistent with the theoretical results.