<p>In order to foster the sustainable development of the paper industry, there is a current imperative to explore new raw materials for paper production to address the issue of resource scarcity. Bamboo stands out as a promising raw material for papermaking due to its inherent advantages (such as short growth period and high yield). Nevertheless, bamboo pulp exhibits a higher non-fibrous cell content compared to traditional raw materials, and the impact of non-fibrous cells on beating characteristics remains unclear. This study is dedicated to examining the ultrastructure of bamboo fibers and the physical properties of paper, aiming to elucidate the influence of non-fibrous cells on bamboo pulp properties. The results indicated that non-fibrous cells facilitate the formation of fiber ballooning structures, which caused damage and shedding of the outer wall layer, consequently affecting fiber properties. Moreover, non-fibrous cells accelerated the generation of fine fibers during beating, and the formation of fines homogeneous structures. While non-fibrous cells aid in the external fibrillation of bamboo fiber, an excessive amount could impede fiber intertwining and hinder the formation of fiber–fiber joints. Hence, investigating the mechanism of non-fibrous cells is crucial for promoting the effective development and utilization of bamboo pulp.</p>