Due to the high percolation threshold and poor strain sensing performance of flexible strain sensing materials prepared with a single filler, in this paper, one-dimensional filler carbon nanotubes (CNT) and in-situ synthesized high conductivity and stable silver@ graphene (AG) composite fillers were synergistically introduced into fluorosilicone rubber ( FSR). Based on the synergistic effect of composite fillers with different geometric effects, CNT/AG/FSR composite materials were prepared. The results indicate that AG conductive fillers have stable performance and controllable structure. The appropriate amount of CNT and AG are uniformly dispersed in FSR matrix to form a three-dimensional conductive network. The flexible strain sensors based on CNT/AG/FSR composite materials show stable and reproducible properties at different tensile strain ranges and motion frequencies. In strain response range of 0 ~ 35% , the sensor exhibit highly linear response with a GF value of 11.79 and a linear correlation coefficient of 0.99. This composite material can accurately monitor human movements such as neck lifting, finger movement, elbow movement, and knee bending, and is expected to be applied in wearable devices and human motion detection fields with high strain response requirements.