Model-based　compensators　have　been　widely　applied　in　force　sensors　with　soft　materials　to　eliminate　viscoelasticity　that　causes　creep　output,　slow　dynamic　response,　and　limits　the　performance　of　the　sensors.　However,　the　lack　of　accurate　characterization　of　high-order　viscoelasticity　and　the　high　computational　complexity　restricts　the　performance　and　application　of　existing　methods.　For　the　above　problem,　we　propose　a　first-order　Volterra　grey　box　model-based　viscoelastic　compensator　for　force　sensors　with　soft　materials.　First,　the　measurement　mechanism　of　the　soft-material-based　force　sensor　is　analyzed,　and　a　grey　box　model　for　accurately　characterizing　the　high-order　linear　viscoelasticity　by　the　first-order　Volterra　series　is　proposed,　without　needing　high-order　spring-damping　parameters　and　their　exponential　operations.　Then,　the　high-order　viscoelasticity　compensator　is　designed　and　directly　linearly　fitted　with　the　variation　of　the　historical　output,　which　avoids　the　computational　complexity　of　the　high-order　creep　compliance　and　its　exponential　parameters　fitting.　Finally,　the　proposed　method　is　verified　with　a　self-developed　soft-material-based　capacitive　force　sensor.　The　real-time　experimental　results　show　that,　compared　with　existing　methods,　the　proposed　compensator　not　only　has　better　compensation　performance,　but　also　has　a　shorter　calculation　time　for　force　sensors　with　soft　materials.　IEEE