Abstract: Based on their inhomogeneity, three distribution pattern categories of the mineralogical structure of sinters, and their formation mechanisms, were detailed. First, based on the identifiable characteristics of hand specimens, the sinters in a steel plant were divided into three categories (Category 1, Category 2, Category 3). Second, according to the identification characteristics of the microstructure of sinters, three distribution patterns of the mineralogical structure for the three categories of sinters were established, those being uniform, concentric annular, and intercalated. The homogeneous mineral phase structures, which have good metallurgical properties, are mostly interlaced erosion and erosion structure, and the mineral phase structures are formed under stable conditions with higher temperature, stronger reduction, and uniform mixture. The concentric annular mineralogical structures from the outside to the inner belt are interlaced erosion structure, erosion structure, and hematite granular structure, separately. These structures formed under deteriorative process conditions and have no obvious adverse effect on the overall structure and metallurgical properties of sinters. The intercalated mineral phase structure, formed by the interlaced erosion structure, hematite granular structure, and calcium ferrate accumulation area, is mostly formed under conditions of lower temperature, unstable air flow, and inhomogeneous mixture. Getting together may lead to the deterioration of the structure and metallurgical properties of the sinter. Finally, the results of a metallurgical performance analysis show that the metallurgical index of Category 1 and Category 2 are satisfactory, and Category 3, with its intercalated distribution pattern, shows relatively poor metallurgical performance due to the inhomogeneous structure. The above results indicate that the research method based on the distribution pattern of mineral phase structure can be conducive to the discovery of the formation mechanism of the mineralogical structure, and can help to control the sintering raw materials and sintering atmosphere. It has certain theoretical value for improving the metallurgical properties of sinter.