The design ideas, key technologies and construction process of a shipborne paleomagnetic laboratory in low magnetic field environment are elaborated based on the construction of a paleomagnetic laboratory for an ocean drilling vessel. The article begins with a brief introduction to the basic principles and research significance of paleomagnetism, and the current technical development status of shipboard paleomagnetic laboratories. The overall design scheme and construction process of the shipboard paleomagnetic laboratory are then elaborated in detail, including the simulation design of the paleomagnetic laboratory, the optimization of the laboratory layout, the innovative structural design, the magnetic shielding technology, the vibration and noise reduction control, and the key construction technology. The key performance indicators, such as the average residual magnetic field in the laboratory and the overall shielding effect, meet the requirements for shipboard paleomagnetic laboratories through the optimization of structure, equipment and material selection, and the innovative application of technologies of hole optimization simulation design, flexible support design, and special construction technology for shielding layers. Finally, a scientifically reasonable debugging and measurement scheme is introduced for detecting the magnetic shielding effectiveness of the shipboard paleomagnetic laboratory, which fully verifies the feasibility and effectiveness of the design and construction of the low-magnetic environment paleomagnetic laboratory.