Abstract: The cold neutrons are guided to the scatter hall from the cold neutron source by the neutron guide tube. Designing a shielding system of the neutron guide tube is necessary for the safety of the workers and providing a low background experiment environment in the scatter hall. The primary design of the shielding system was completed. In this paper, the calculated shielding effects were presented by McStas and MCNP with the method of dividing the whole system into several sects. The results indicate that the primary design scheme of the shielding system is feasible.