In order to investigate the fracture initiation mechanism and influencing factors of weakly consolidated biological mudstone in the Quaternary system of the Qinghai oilfield, a series of experiments was currently underway. Rock-based experiments were being used to determine the mineral composition and mechanical properties of the weakly consolidated biological mudstone. Additionally, fracture initiation experiments were taking place to investigate the crack initiation law in detail, while taking into account cementing quality and perforation depth. The results show that cementing quality and perforation depth are critical factors that affect fracture initiation. Specifically, the results indicate that poor cementing quality can lead to wellbore enlargement, making it difficult to achieve the conditions necessary for fracture initiation. Conversely, deep perforation reduces the plastic deformation of the fracture initiation tip and lowers the fracture initiation pressure. These results will have significant implications for the optimization of fracturing process parameters for weakly consolidated biological mudstone in the Quaternary system of the Qinghai oilfield.