Abstract: This paper introduces the actualities of internal coating technology and basic technological process of internal coating spraying method at home and abroad. A detailed discussion is given about the basic operating principle, construction, main design scheme and experiment process of the crucial sections -internal mechanical shot blasting and internal spraying in the internal coating assembly line. The experiment and survey report indicate that the spraying internal coating by the two developed equipments meet the demand of the related standards for Wesl-to-East Gas Pipeline Project, and various technological specifications satisfy the requirements of industrialized large scale internal coating operation.