Abstract: Considering the special requirements for the project time and cost control during the difficult period of the petroleum industry, the paper introduces the whole design process of inventory subsea pipes by taking the extended test and the oil & gas recovery project in someplace of China sea as example in which the total length of the subsea pipe is 7.5 km. According to the results of calculation and pipe repair, the inventory pipes meet the requirements of the project design life and quality. In addition, in order to improve the efficiency and quality of the pipe laying, the measures of classification and loading of the pipes with different specifications were carried out according to the internal diameter tolerance. The efficiency of the pipe laying in this project was greatly improved than the original plan, and the success of pressure test was achieved in one time. The successful experience of the project in technology and project management can provide a reference for similar projects at sea.