Numerical simulation of the effect of the anode magnetic shielding on the magnetic field and ion beam in a cylindrical Hall thruster is presented. The results show that after the anode is shielded by the magnetic shield, the magnetic field lines near the anode surface are obviously convex curved, the ratio of the magnetic mirror is enhanced, the width of the positive magnetic field gradient becomes larger than that without the anode magnetic shielding, the radial magnetic field component is enhanced, and the discharge plasma turbulence is reduced as a result of keeping the original saddle field profile and the important role the other two saddle field profiles play in restricting electrons. The results of the particle in cell (PIC) numerical simulation show that both the ion number and the energy of the ion beam increase after the anode is shielded by the magnetic shield. In other words, the specific impulse of the cylindrical Hall thruster is enhanced.