Abstract: High speed continuous casting，continuous casting and rolling process with high efficiency，energy saving and low cost advantages have been rapidly popularized and applied，but encountered development bottleneck due to an increasing frequency of mold flux entrapment in high speed continuous casting and entrapped mold flux defects in rolled products. In this paper, the formation mechanism of mold flux entrapment and its main influence factors were analysed，and characteristics of slag entrapment defect in the slab，hot rolled products and cold rolled products，and their evolution law were briefly described. Finally the control measures of mold flux entrapment in high-speed continuous casting were reviewed. In view of the shortage of existing measures to adapt to the development of high-speed continuous casting，the key development directions are put forward，such as electromagnetic control of the flow field in mold，intelligent control of mold liquid level and development of high-performance mold flux，which can provide reference for promoting the highquality development of high efficiency continuous casting，continuous casting and rolling process.

Key words: high-speed continuous casting, slag entrapment defect, mechanism of mold flux entrapment, electromagnetic control of the flow field, mold level intelligent control