研究了超导环向场磁体线圈盒对磁场的屏蔽效应。通过将线圈盒上的磁场分解为两个垂直的分量可以求得磁场两个分量在线圈盒中感应的涡流。线圈盒对磁场的屏蔽效应则与涡流产生的磁场有关。研究结果表明,线圈盒对磁场的屏蔽效应因磁场的方向不同有很大的差别,线圈盒对切向磁场的渗透呈现较强的屏蔽效应。 The shielding effect of the superconducting hoop field magnet coil box on the magnetic field was studied. By decomposing the magnetic field on the coil box into two perpendicular components, the eddy current induced in the coil box by the two components of the magnetic field can be determined. The shielding effect of the coil box on the magnetic field is related to the magnetic field generated by the eddy current. The results show that the shielding effect of the coil box on the magnetic field is greatly different due to the different magnetic field directions. The penetration of the coil box to the tangential magnetic field shows a strong shielding effect.