Climate change has been occuring in recent years. The extraordinary changes lead to high temperatures, floods, and typhoons that become a significant threat to people's lives and property. Therefore, engineering methods have become important, as they decrease the level of people's loss caused by natural disasters. Synthetic fibers have been commonly used in geotechnical engineering field since their invention, and are now widely available. Whether geotextiles are made using fabrics or nonwoven fabrics, water permeability and appropriate strength are their indispensable properties in reinforcement, separation, filtration, drainage, and protection. In this study, polyester (PET) filaments and nonwoven fabrics are combined using hot pressing, during which different weight amounts of filament are used. The composites are tested for delamination strength, tensile strength, tear strength, burst strength, and puncture strength to characterize the filament-based geotextiles. The experimental results show that a high needle punching depth has a negative influence on the strengths of geotextiles. Moreover, the geotextiles exhibit the optimal tensile and tearing strength when they are hot pressed at 170 degrees C, and optimal burst strength and puncture strength when they are hot pressed at 180 degrees C.