Liquid metal is a kind of functional materials with both electrical conductivity and fluidity, and has gained widespread attention for its excellent conductivity and deformation capabilities. Fiber materials, as the common flexible substrate, have shown broad application potential in many fields due to their excellent stretchability, breathability, and weavability. In order to solve the problem of poor flexibility of electronic components and difficulty in meeting wearable and intelligent requirements, starting from the matrix and conductive materials, combining with the advantages of stretchable deformation and flexibility of fiber materials and the high conductivity and room temperature fluidity of liquid metal (LM), LM-based fiber composite materials were prepared, which have been widely used in fields such as human motion monitoring and energy storage. Firstly, the control strategies for the LM in terms of chemical stability, electrical and thermal properties and the methods of combining with fiber materials are introduced, including coating, injection and electrospinning methods. Then, the research progress of LM-based fiber composites in sensing, electromagnetic shielding, energy harvesting and storage are emphasized. Finally, suggestions are proposed for the improving of its performance and addressing the remaining issues in current research, and future development directions are anticipated.