The solvent-free epoxy coating has excellent performance as an external anticorrosive material for casing,and is easy to be sprayed automatically.It is gradually being widely used in Longdong oil area of Changqing oilfield.The process of solvent-free epoxy external anti-corrosive coating pre-construction for the oil well casing pipe was introduced,the process factors that affect the coating quality were analyzed,and a series of quality improvement measures were put forward.