Abstract: With the rapid development of offshore oil and gas fields, especially the development of gas fields, the demand for natural gas compressors is increasing. The advantages and disadvantages of the assembly design and manufacturing plays a vital role in the normal operation of natural gas compressors. At present, domestic manufacturers generally cooperate with foreign manufacturers to design and construct the sled of compressor, but compressor main engine and motor mainly depend on imports. Based on the current situation of domestic and foreign mainstream compressor manufacturers and JZ25-1S Ⅱ natural gas compressor project, the key and difficult points of the base prefabrication and key assembly process are described in detail.In addition, the advantages and disadvantages of the whole and the split assembly processes for the compressor with twolayer operating platform are discussed.