The paper considers the application of the tank wall design, which is a three-layer panel consisting of two shells, between which there is a truss filler. Such a filler is a repeating spatial structure consisting of pyramids or tetrahedrons.The analysis of references concerning such a construction is carried out. As a result of the analysis, it was revealed that the three-layer panel with a truss filler found its application in aviation and rocket engineering, and all studies were carried out for structures with thickness not exceeding 150 mm, and the applied load was evenly distributed over all surfaces.To research the stress-strain state of the tank structure, two numerical models were created in the SCAD Office software package. All active loads are collected. The calculation was carried out for tank structures, in the inter-wall space of which pyramids and tetrahedrons were located.The technology used relates to cross-cutting digital, namely digital design and modeling, which is currently included in the concept of technological development of our country.The search for the optimal inclination angle of the rods was carried out in the range from 40° to 60°. Five calculations were performed for each placeholder in the corresponding ranges.As a result of geometric parameters dependencies researches of the double-walled tank wall, the inclination optimal angles values of the pyramidal and tetradrael rods fillers for the wall of a tank of 50000 m3volume were obtained. There are obtained dependences to determine the optimal inclination angle of the rods of the truss filler for a tank of any volume, using relative values, as well as the values of forces arising in the rods of the filler depending on the hydrostatic column of the liquid.