Abstract: Downhole fluid loss is a major problem in cementing ?177.8 mm casing in HFY Oilfield. Based on the cementing quality analysis of ?177.8 mm casing in HFY Oilfield, the cementing engineering characteristics and cementing technologies, the main problems and the suggestions for cementing technologies improvement were addressed in this paper. In line with the technical status in HFY Oilfield, it was suggested that, while maintaining the existing successful experiences, research and study should be enhanced on the assessment of loss pressure of drilled formations and the determination of thief zones, hole cleaning condition and improving the ability of cement slurry to prevent loss, so as to continuously improve the cementing technology for ?177.8 mm casing.