Black glazed ware is one of the most common varieties in the colored glazed ware of ancient China. Due to the easy availability of raw materials, it is fired everywhere, especially in the Song Dynasty. At present, α-Fe₂O₃, ε-Fe₂O₃, Fe₃O₄ has been found in ancient black glazes, but there are few reports on the influence mechanism of iron-rich raw materials on crystal types. Therefore, the Qingshitou and Hongshitou from the Dayu Town of Ruzhou and the Zijintu from Hangzhou were chosen as the study subjects. They were studied comprehensively by an X-ray fluorescence spectrometer (XRF), X-ray diffractometer (XRD), confocal laser Raman spectrometer (Raman) and scanning electron microscope (SEM). Firstly, the iron-rich raw material's chemical composition, phase and type of iron-containing phases were compared and analyzed by spectral information. And then, they were used alone as the raw material for glaze making to study the change mechanism of the iron phase after firing microstructure and spectral information. The results indicated that the contents of CaO, MgO and K₂O in Qingshitou were high, which could reduce the high-temperature viscosity of glaze melt and increase its fluidity. It was conducive to particle migration and crystal nucleation and growth. The content of SiO₂ in Hongshitou was only 61.36%, and it contained calcite crystal, so the melting temperature was low, and it was easy to form glass phase. At this time, iron existed in an ionic state. Besides, the contents of SiO₂ and Al₂O₃ were high in the Zijintu, and the contents of CaO, MgO and K₂O were low, so its melting temperature was high. Three kinds of iron-rich raw materials were melted into glazes. For the Qingshitou glaze, part of α-Fe₂O₃ had a decomposition reaction. The black magnetite (Fe₃O₄) was precipitated, as well as the concentration of α-Fe₂O₃ around the bubble increased continuously and escaped with the bubble rising to the glaze surface, resulting in the precipitation of brownish red crystal flowers. Based on this, Qingshitou was suitable as raw material for the black glaze. The Hongshitou glaze was mainly glass phase, and no obvious iron crystal was found. Hence, it was suitable as raw material for the celadon glaze. In the Zijintu glaze, the glass phase content was little, and the high content of SiO₂ and large particle size of α-Fe₂O₃ were beneficial to the formation of rod-shaped ε-Fe₂O₃. Therefore, the glaze surface was dark brown with a metallic luster. It showed that Zijintu was suitable as raw material for the Zijin glaze. This study discussed the influence of iron-rich raw materials on the type of iron oxide crystallization, its glaze color and enamel, and revealed the physical and chemical process of iron oxide crystallization. It had important reference significance for studying ancient iron-based crystal glazes and the preparation of modern magnetic materials.