The injection solution of ASP flooding in X12 area reacts with formation minerals to form scales, and then precipitates from the produced fluid and accumulates in the produced wells, which is easy to cause scaling and affect production. Through the analysis of scale sample, the main components of scale are defined, and the scaling regularity is studied. The purpose of cleaning and preventing scale in production wells is realized by using open scale prevention pump, pre⁃scaling process pipe string and dropping dosing measures. The results show that carbonate scale is the main scale component of weak alkali ASP flooding in X12 area, accounting for more than 78% of the scale sample quality; with the ASP injection, the vale of CO〖_(3)^(2-)〗 and pH increase gradually, while changes of Ca〖^(2+)〗+Mg〖^(2+)〗+Ba〖^(2+)〗 show the shape of curve of "rising⁃stabilizing⁃falling"; the scale mainly occurs after the ASP injection of 0.23 PV, and the concentration of CO〖_(3)^(2-)〗exceeds 140 mg/L. From the right shoulder of the⁃type concentration line of Ca〖^(2+)〗+Mg〖^(2+)〗+Ba〖^(2+)〗 above pH 8.3, the descending range of 0~15% is gradually accelerated; a set of underground surface scale prevention measures is formed by putting open scale prevention card pump at the extraction end, adopting pre⁃scaling process pipe string, and installing drip dosing device in the fouling well, with an average period of 167 days prolonged. And a set of underground surface scale⁃proof technical system was formed. The research has certain guiding significance for the development of combined flooding and scaling prevention technology.