Abstract: A large number of construction data show that construction pressure is often higher than the predicted pressure in coal rock fracturing, and most wells have no obvious fracture pressure. Proceeding from physical model experiments and comparison between experimental data and construction data, we explain the phenomenon. Construction pressure is result of fracture propagation in ground, which is close to fracture morphology. In this paper, the influence factors of fracture morphology were investigated and the experimental method was applied to fracture various types of cracks artificially. Results of crack initiation show that: fracture morphologies mainly include single fractures, parallel multi-fracture, intersecting multi-fracture, and the pressure curves of different fracture morphologies were different. Single fracture has obvious fracturing pressure, and the extension pressure is close to the minimum horizontal principal stress. The pressure curve of parallel multi-fracture is smooth, without obvious fracture pressure. Intersecting multi-fracture has multi-fracturing pressure. Propagation pressure of multi-fracture is higher than that of single fracture. According to the field construction pressure and the experimental conclusion, the fracture morphology of the two wells in south Shizhuangnan Mine is analyzed and the measures are taken to achieve better results.