This paper takes a certain cassiterite polymetallic sulfide ore deposit in Inner Mongolia as its research object, using methods such as the third-generation automatic quantitative analysis for mineral parameters (AMICS), a systematic process mineralogical study was conducted on the chemical composition, mineral composition, and grain size distribution of the ore, as well as the grain size, liberation characteristics, and occurrence characteristics of the main minerals, and the occurrence state of the primary target elements. The results indicate that the primary valuable elements in the ore are Cu, Ag, and Sn. Cu is primarily present as sulfide copper minerals such as chalcopyrite and tetrahedrite, Ag is mainly distributed in tetrahedrite in a solid solution form, and Sn is primarily present as cassiterite. Under coarse grinding conditions, although the liberation degree of individual sulfide minerals is less than 70%, the liberation degree of sulfide mineral aggregates reaches 80%. Considering the brittle and fragile nature of cassiterite and its tendency to occur in association with sulfide minerals, it is recommended that under coarse grinding conditions, mixed flotation be first used to recover the copper-silver sulfide mineral aggregates, followed by gravity separation to recover cassiterite. This provides a reference for the development and utilization of similar cassiterite polymetallic sulfide ores in Inner Mongolia.