Aiming at the deep seabed sediment sample which was collected by the whole-deep sea sediment airtight sampler, a pressure maintaining container was designed to meet the requirement of submarine in-situ samples which come from the whole-deep sea life evolution scientific research. Firstly, according to the volume and the pressure maintaining performance requirements of the pressure maintaining container, the preliminary design of geometric structure parameters of the pressure maintaining container was studied and the 3D geometry model of the pressure maintaining container was established by using the 3D software Solidworks. Secondly, the pressure maintaining performances of the pressure maintaining container were calculated and analyzed based on the finite element analysis ANSYS software for the case of whole-deep ultrahigh pressure environment. Finally, the pressure maintaining performances of the pressure maintaining container was analyzed under different thickness and diameter of the pressure maintaining container. The result shows that in the same wall thickness condition, the container maximum stress increase with the increase of ressure maintaining container diameter, while the container weight gradually decrease.