The Sijiaying iron deposit is the single largest iron deposit in China, with important economic and strategic resource significance, accounting for about one sixth of the total iron ore resources in eastern Hebei Province. It has been more than 100 years since the discovery of the Sijiaying deposit in 1914. It has a long history of exploration and research, and has provided a series of important research insights: the metallogenic material came from the mixed solution of submarine high temperature hydrothermal solution and seawater; the fold and fault structures in the mining area control the final location of the ore body; the original metallogenic geological setting of the deposit is probably a back- arc basin; there are two kinds of rich iron ores in the mining area; primary sedimentation and hydrothermal reformation, later tectonic movement may have led to further enrichment. Based on a review of the research progress and existing challenges of Sijiaying deposit, this paper proposes that the middle and upper strata of Luanxian Group are the target horizons for further deep prospecting, while the high- grade iron ore should be found in the thick and large low- grade ore body; identifying the character of faults is helpful to infer the location of deep ore bodies, and the turning end of folds and the intersection of faults are helpful to the occurrence of high- grade iron ores; magnetic anomaly and gravity anomaly are important marks for prospecting large and rich deposits; the location near migmatization and hydrothermal alteration is more conducive to the search for high- grade iron ore; it is suggested that a follow- up prospecting work should be carried out in the deepening direction of the orebody on the west side of the mining area; with the increase of burial depth, weak magnetic anomalies are also worthy of greater attention.