In order to accelerate the transformation and upgrading of the construction industry in the direction of industrialization, digitization and intelligence, many universities are actively developing intelligent construction majors and offering a series of new courses. Among them, construction 3D printing is one of the featured courses, and its teaching content involves relevant knowledge in the fields of machinery, materials, and information. However, there are some problems with traditional classroom teaching and large-scale experiments, such as the low interest of students in learning and the low efficiency of knowledge understanding, as well as the large-scale experiments are limited by the high cost, long production cycle, and low finished product rate of 3D printing. Therefore, it is necessary to explore online-offline hybrid teaching mode to stimulate students' learning interest and fully cultivate their practical spirit and innovation ability, so as to effectively enhance the teaching effect. This study discusses the content design and practical operation of online-offline hybrid teaching mode by taking the construction 3D printing course in the intelligent construction program of Huazhong University of Science and Technology as an example. The course builds a virtual simulation system for 3D printing, which provides tools such as 3D model format conversion, automatic model detection, and model repair, allowing students to perform virtual printing operations and make adjustments to the parameters of the printed model at the lowest cost and in the shortest time. In addition, the industrial-grade six-axis robotic arm-based 3D printing equipment is used to carry out offline printing practice, and the establishment of a standardized printing process ensures the accuracy of the printed components. Through the concrete printing instance of the "Moon Pot Zun" shell structure, the complete learning process under this mode is introduced. This teaching mode can meet the "three-one" talent cultivation concept of mastering a software language, driving a hardware device, and solving an engineering problem, which can provide a useful reference for other universities to carry out the teaching of construction 3D printing.