Abstract: The development degree of natural fractures in coal seams directly affects the storage and seepage capacity of coalbed methane (CBM) and introduces significant heterogeneity during CBM development activities such as drilling, fracturing, and drainage. Currently, the detection and characterization of natural fractures in the in-seam sections of horizontal wells present considerable challenges. This study focuses on coal rocks from the Eastern Ordos region, employing quantitative fracture characterization, acoustic wave testing, drilling experiments, and drill cuttings analysis based on the Rosin-Rammler model to systematically investigate the quantitative relationships between fracture parameters, acoustic parameters, drilling parameters, and cuttings parameters. The results indicate that fracture linear density ρ₁ and fracture area ratio ρ₂ are negatively correlated with the average acoustic wave velocity v; Higher fracture development degrees significantly impede acoustic wave propagation. Drilling rate w and cuttings production rate q show weak positive correlations with fracture parameters. The average cuttings particle size d₀ and median particle size d₅₀ are positively correlated with fracture parameters but negatively correlated with the breakage degree index λ, while showing no significant relationship with the breakability index n. In a field application case, the fracture development degree in the in-seam section of surface CBM well X-2 was predicted based on the above research, leading to the identification of three intervals suitable for fracturing. Finally, based on the response characteristics of cuttings to fracture development degree, coal rocks are classified into three categories: Type I coal, with low fracture development, coexisting exogenous fractures and cleats, and dominated by fine cuttings; Type II coal, with moderate fracture development, primarily containing exogenous fractures, and showing a shift in cuttings size distribution towards coarser grades; and Type III coal, with high fracture development, dominated by dense cleats, and mostly producing coarse-grained cuttings. This study reveals the influence of coal seam fracture development degree on drill cuttings size distribution during in-seam drilling. Cuttings logging based on particle size distribution can serve as an effective auxiliary method for predicting fractured coal rocks, providing a scientific basis for selecting optimal fracturing sweet spots.