Abstract: The mechanism of magnetohydrodynamics (MHD) controlling onsupersonic flat-plate turbulent boundary layer was explored in theory andnumerical simulation. The collision frequencies between theelectron-molecules and ion-molecules at the boundary layer were obtained bylow frequency approximation in the plasma, and the force balances forelectrons and ions were set up to solve the plasma velocities, polarizationelectric field and the boundary layer velocities. HLLE schemes and LU-SGSmethod were used to numerically solve the sst-k\omega turbulent model.The results show that, (1) the relative error between numerical results andtheoretic results are in the range of 7%; (2) in the absence of electricfield, the Lorentz force can decrease the skin friction. With an externalelectric field applied, the low velocity fluid in the boundary layer can beaccelerated; (3) in the outer layer of boundary layer, the interactionparameter decreases with the distance to the wall, but in the inner layer asthe viscous force dominates the flow, the interaction parameter increaseswith the distance to the wall.