High-temperature superconducting (HTS) pinning maglev has achieved rapid development in recent decades. It has a great development prospect and potential for high-speed application. The levitation system of HTS pinning maglev is mainly composed of Dewar with built-in HTS bulks and permanent magnetic guideway (PMG) laid along the line. The HTS bulks receive the pinning force in the gradient magnetic field generated by the PMG, providing levitation and guidance force for the maglev train. However, for the levitation system, there is a Dewar shell between the HTS bulks and the PMG. This conductive material will also generate eddy current in the changing external magnetic field, and affect the interaction between the HTS bulks and the PMG. The eddy current is related to the conductivity of the material. Therefore, when investigating the dynamic levitation force of the HTS pinning maglev system, it is necessary to consider the effect of Dewar shell. In this paper, stainless steel and aluminum alloy are used as the shell materials of the Dewar respectively. Through experiments and simulations, the shell materials’ influence on the Dewar's overall dynamic levitation force is explored, and suggestions are provided for the selection of HTS pinning maglev Dewar material.