Abstract The problem of safety optimization of the high pressure compound vessel is presented. The safety for both assembly and working states is considered. Two different objective functions are taken into account, corresponding to two methods of loading from actual stress state to the limiting brittle fracture state. For the vessel of the given type consisting of n parts (the matrix and n−1 steel rings), the number of design parameters is 2n−1. Design parameters were preoptimized on the cylindrical compound vessel model. Because of the cost-effectiveness of finite element calculations, only two variables having the greatest influence on the matrix safety were taken into account. These were the radius and the overlap of the first ring. For optimization the variable metric method is used.