The ongoing advancement in the exploration and development of oil and gas resources has shifted focus towards deep and ultra-deep layers, emerging as the primary arena for oil and gas exploration and development in China. The intricate fractured reservoir environment, characterized by a narrow safe density window and borehole breathing during drilling, presents substantial challenges to ensuring safe and efficient drilling operations in deep reservoirs. Borehole breathing-induced return of drilling fluid can be easily misinterpreted as a well kick, leading to the implementation of erroneous well control measures that significantly impact the safety and efficiency of deep drilling. To gain a more comprehensive understanding of the dynamic response mechanism associated with borehole breathing in fractured reservoirs, as well as to elucidate alterations in fluid and rock behavior during this process, this study has developed an innovative model for simulating borehole breathing within fractured reservoirs. This model is grounded on the permeability and fluid flow principles governing non-Newtonian fluids, employing dual porous medium stress coupled with flow methodologies to effectively simulate and quantify both the loss and return of drilling fluid within the borehole during instances of borehole breathing within deep fractured reservoirs, along with changes occurring within fractures. The model underwent validation through the utilization of field data and case studies.