Abstract: The laser welded steel sandwich structures have been used in ship structures. The strength of joint between sandwich panels is one of the key concerns for designers. The models for analyzing the strength properties of two typical joints of I-core steel sandwich panel were proposed by ANSYS，in which shell-solid assembly together with submodel method was employed. Compared with the results of the model wholly meshed with brick element，the computational accuracy of stresses near the welded region between the panel and joint member under in-plane load and out-of-plane load by using four kinds of shell-solid assemblies and submodel method was testified. They were multipoint constraints，degree of freedom coupling，defining constraints equations and creating shell element on the shell-solid interface. It is shown that the balance between good accuracy and convenience in operation can be reached by selecting suitable shell-solid assemblies，such as multipoint constraint with shell-solid constraint option and creating shell element on the shell-solid interface，together with sub model method and right mesh of main model. The computational scale is greatly reduced by the proposed models.