Abstract: Flexible stress sensor is a key component in wearable devices．Sensitivity of flexible stress sensor determines detection properties．Thus, investigation of sensitivity influence factors in the preparation process could help to improve sensor properties and controllable preparation．In this study, a novel series of flexible stress sensors were prepared by combining Ag nanowires (AgNWs) with conductive sponge substrates．Structural characterizations show that AgNWs adheres to the network of conductive sponge uniformly．When stress is applied, conductive sponge presents large-scale deformation and AgNWs shows subordinate deformation in microstructure．Multiple deformation including conductive sponge and AgNWs microstructure could enhance the sensitivity of flexible stress sensor．The flexible stress sensors in this work exhibit excellent sensitivity and repeatable durability．The influence of different dielectric materials, the thickness of dielectric layer and layers of dripping AgNWs is investigated carefully．The preparation process is optimized and can be controlled．The preparation process in this study is simple and is fit for large-scale production, with great application prospects in the future．