Abstract: With the rapid development of the petrochemical industry's internationalization process, traditional construction methods can no longer meet its current rapid development needs. With the emergence of new construction methods, traditional construction methods are gradually being replaced. Modular construction, the advantages of enhancing the depth of prefabrication, reducing on-site installation, shortening the construction period, reducing costs and increasing efficiency have emerged in various international projects, which has brought a qualitative leap in the development of the petrochemical industry. Based on this, this article analyzes the problems encountered in modular construction in a CNOOC project in order to provide a reference for similar construction.