Based on high-precision multi-beam, single-beam, side-scan sonar and other data， the authors found two submarine sand wave groups in the offshore areas of Fujian's Minjiang estuary and Sanshawan estuary, respectively. In this paper, the geomorphic characteristics of the development of the submarine sand wave were analyzed in detail. According to the shape of the development of the sand wave and the trend of the sand ridge line, it can be divided into three types: flexural sand wave, linear sand wave and transitional sand wave. Both sand wave groups show a slower slope on the tide and a steeper tide， which is characterized by branching at the end of the sand wave and is accompanied by a certain degree of bending deformation. Sources of sedimentary materials and hydrodynamic environment are two main factors that control the development of sand wave groups on the sea floor. The reduction of sources of near-shore bedrock erosion materials, river sediment materials and ocean current transport materials in the study area breaks the material supply that maintains the dynamic balance of sand waves. Underflow scouring provides the starting conditions for seabed sediments. Combined with the development characteristics of sand ripples, residual dunes and seabed sand waves, the authors hold that sand waves have certain activities and have a law of continuous migration to the steep side of the slope. Finally, through the analysis of the causes and evolution rules of sand wave activity, the authors discussed the influence of the existence of sand wave on the application of marine engineering in detail, and put forward the corresponding preventive measures, which provides a certain reference for the construction of offshore seabed engineering and disaster prevention.