With the rapid development of human?computer interaction, electronic skin, wearable electronics and other emerging fields, flexible strain sensing materials as one of the core components have become the hot spot of the current research. The conductive polymer composites composed of conductive material and flexible polymer have the advantages of good flexibility, light weight, easy processing and forming, and the conductive property of the material changes under strain stimulus, so it can be used as flexible strain sensing material. This paper reviewed the classification and characteristics of flexible strain sensing materials based on conductive polymer composites, introduced the strain response mechanism of different sensing materials in detail, and summarized the factors that affect the strain sensing performance of conductive polymer composites.