It is important to consider the suspension of the submarine pipelines, analyzing the stability of the submarine pipelines. Because of the complex geological conditions of the seabed, the buried pipelines hung on the seabed are affected by waves. Once occurred the suspension of the pipelines, the suspended pipelines would be destroyed under the action of the external environment. The pipelines accidents lead to a great loss of property and bring the pollution of the marine environment. Because most of the oil fields are located in the offshore areas in our country, the characteristics of shallow water waves should be considered.Based on the solitary wave theory, and considering the non-linear effects of the shallow water waves, the hydrodynamic loads on the suspension of the pipelines was calculated in this study.For the common forms of hanging pipelines, considering that the max bending stresses are less than the material's allowable stress, the formula for the allowable free span length is derived. Finally, taking the submarine pipelines works in Bohai bay as a case history, the allowable free span length of the submarine pipelines was calculated.The calculation results show that a part of the pipelines' span lengths exceed the allowable span lengths, and they must be reinforced.