Hard inclusions such as fluid inclusions are commonly hosted in coal seams during coal mining operations, and the hardness of such inclusions is significantly higher than that of the coal matrix. When a shearer drum cuts a coal seam containing inclusions, problems such as a sharp increase in the instantaneous impact load on the cutting system and abnormal wear of pick cutters are prone to occur, which seriously impairs the operating efficiency of the shearer. It is thus imperative to conduct a systematic study on the influence laws of key factors (including inclusion size, spatial distribution position and structural parameters of the shearer drum) on the dynamic cutting characteristics, cutting resistance characteristics and pick force-bearing characteristics of the drum. In this paper, a research method combining theoretical analysis and numerical simulation was adopted to systematically investigate the influence laws of inclusion size parameters, spatial position parameters and the included angle between adjacent picks on the number of participating cutting picks during the process of cutting inclusions. Taking the number of picks involved in cutting inclusions as a key intermediate variable, the internal correlation mechanism between the size characteristics of inclusions and the cutting characteristics of the shearer drum was deeply analyzed. The research findings show that the size of inclusions along the traveling direction of the drum has a significant effect on the number of picks cutting simultaneously. Especially in the middle of the coal seam, even small inclusions can cause more picks to work at the same time, leading to a load rise. Increasing the included angle between adjacent picks (e.g., from 15° to 25°) will increase the minimum size requirement of inclusions in the vertical direction by about 15%, thereby reducing the number of picks in simultaneous contact and helping to lower the overall load. The research content and conclusions of this paper can provide ideas and a theoretical basis for the structural design of shearer drums for cutting inclusion-rich coal seams.