Introduction. The war in Ukraine caused significant damage to the economy, but also provided many new opportunities, made adjustments to the paradigm of post-war economic development, in particular, in view of the need to rebuild industries and ensure the reliability of their operation in the future, the variability of logistics supply routes. The complexity of post-war reconstruction is aggravated by the fact that Ukraine must modernize the defense industry and, at the same time, reduce the country's budget deficit, which requires an increase in budget revenues. The radical changes necessary for this will require optimization of the sectoral structure of the country's economy.
 Aim and tasks. The purpose of the study is to create a methodological approach to the sectoral optimization of the national economy in the post-war period and, for this, to develop a structural-mathematical model, determine priority areas of development of branches, and mechanisms of structural optimization of branch development.
 Results. A methodological approach to sectoral optimization of the national economy in the post-war period was developed, in which a structural-mathematical model was implemented. To optimize the industry structure, the use of a "trigger" mechanism is proposed: when the stimulation of the development of individual projects in high-tech industries leads to the rapid development of adjacent sectors of the economy, The need for comprehensive use of intensive and extensive mechanisms of post-war economic restructuring is indicated due to the specifics of the development of industries, the significant industry differentiation of damages and losses, and the need for expenses for the transformation and restructuring of industries. A diversification approach with the selection of short-, medium-, and long-term industry strategies was proposed.
 Conclusions. The developed mathematical model allows for the combination of sectoral optimization strategies of the economy and optimization coordination of sectoral strategies at the national level. An assessment of the costs of reconstruction and industry transformation was carried out, and the application of internal financing mechanisms, in particular, an increase in the level of added value, was substantiated. The mathematical model illustrates the possibility of maximizing the added value. Considering this, directions for industry optimization and prerequisites for restoration, reconstruction, and optimization of the industry structure in the post-war period are proposed. The given areas of industry-wide impact of the trigger mechanism indicate the prospects of its introduction.