Accurate prediction and reliable analysis of morphology and performance of major equipment is one of the key technologies to realize its intelligence and independent innovation. As a link connecting the physical world and the digital world, digital twin can realize true mirror of the whole life for material design of physical entity, structure design, manufacturing, and operation and maintenance management in digital space. Facing the geometric morphology and mechanical performance of major equipment, and analyzing the difficulties in establishing its digital twin, a solution of computation -measurement combination based on measurement data and mechanism model is proposed. Considering the timeliness and accuracy requirements of the twin model, a shape-performance integration digital twin(SPI-DT) framework for major equipment is built. Additionally, six specific problems faced by building the digital twin of major equipment are discussed in detail, including unrealizable calculation, inaccurate calculation, delayed calculation, unmeasurable data, incomplete measurement and inaccurate measurement, and the relevant solutions and key technologies are given. The feasibility and validity of the proposed framework and key technologies are described by combining typical case, which provides a theoretical and methodical reference for the further application of digital twin in major equipment. Finally, the future development trend and further challenges of digital twin of major equipment are discussed. © 2022 Editorial Office of Chinese Journal of Mechanical Engineering. All rights reserved.