This paper studies the damage pattern of geotextiles during construction of flexible mattress in deep water areas with strong wind and wave，and discusses the stability improvement technology of soft mattress in complex hydrological environment in combination with the characteristics of geotextile soft mattress including protection，reinforcement，filtration，isolation，integrity，and strong adaptability. The result shows that measures taken for the geogrids and soft mattress such as reinforcement，increasing buffer layers，three-layer composites，and whole-length treatment can better solve the problem of soft mattress damage due to large and frequent wind and waves and few construction days.