Abstract: Constructing large-size oil tanks at present is an inexorable trend. In China, more and more large-sized oil tanks have been continuously constructed as Chinese petroleum industry rapidly develops. The method introduced advanced technology from abroad and assimillated at home is adopted in designing and constructing the large-sized tanks. In the "70 × 10⁴ m³" oil tanks project, taking the manufacture of bottom plates for the 3 oil tanks with the capacity of 100000 m³ in Qinhuangdao as an example, the localization of manufactures for bottom plate of tanks has been realized through introducing and assimillating advanced technology from Nippon Steel, and the practical experiences have been obtained from the project.