Abstract: Aimed at the softening water obtained by ion exchange resin, a composite corrosion and scale inhibitor LXZH-1481 was developed. By using this corrosion and scale inhibitor, the corrosion rate reached below 0.0661 mm·a-1, and fully met the requirements of industry. This composite corrosion and scale inhibitor did not contain molybdate, nitrite and other harmful ingredients, and thus was friendly to environment. In addition, its cost was moderate. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses showed that a layer of precipitation membrane formed on the carbon steel surface, which protected the carbon steel effectively.