Abstract:The gravitational and environmental stray magnetic fields will introduce measurement noises and system errors during atom interferometric measurement process. Usually, the magnetic shield material sheets are rolled and welded to become the cylindrical segments, which are spliced to form the cylindrical magnetic shield device with enough length. To clarify the influence of this fabrication method on the magnetic shielding performance, the variations of residual magnetic field distribution in shielding area caused by the number of shield layers, the axial and transverse weld seams and adding caps on both ends of the shield device are analyzed in detail in this paper. The results show that the existence of the axial weld seam with the width of 4 mm has little influence on magnetic shielding, however the presence of the transverse weld seam with the width of 4 mm on the shield with lower relative magnetic permeability will introduce obvious magnetic flus leakage, adding caps on both ends of the shield device may reduce the residual magnetic field intensity, but it can hardly enlarge the region of uniform magnetic field. Based on the analysis results, a duallayered cylindrical magnetic shield device used for the interference area of the upwardprojectile cold atominterferometry gravimeter was fabricated, and the actual measurement results reveal that a uniform magnetic field region with length of 700 mm and unevenness of 4 nT is obtained after demagnetization, which satisfies the requirements of atom interferometric measurement, and has good consistency with the simulation results. .txt