The traditional serial working mode is no longer adopted for development of modern large ship products, instead, remote collaborative design with the support of parallel engineering is carried out, and the full three-dimensional design and modular construction of the total section provide powerful tools and means for ship development in this way. In order to effectively control the parallel collaborative development process of large ships combined with the characteristics of full three-dimensional design and modular construction of large ships, and in view of the lack of detailed evaluation of design status control compared with maturity, and mismatch with the modular construction mode of the total section, a digital mock-up maturity assessment method is proposed. Through the valuation calculation method and key process domain method, a more accurate and reasonable digital mock-up maturity value is defined, and a four-level digital mock-up maturity assessment system covering equipment, region, total section and product is established, and a control method for maturity changes is proposed. This maturity assessment can realize third-party evaluation and review, and the management unit and the modular construction mode of the total section are closely matched, which can support the construction enterprises to carry out corresponding production design, process design and construction according to different maturity digital mock-ups, improve the parallelism of design and construction and development efficiency.