Ultralight, highly compressible and superelastic carbon materials hold great promise in wearable and flexible electronic devices, but the fabrication remains to be a challenge because of the brittleness nature of carbon. Herein, a carbon aerogel with ultralow density yet high mechanical performance is successfully fabricated from graphene oxide (GO) liquid crystal stabilized bubbles with the enhancement of cellulose nanofiber (CNF). The incorporation of CNF into reduced graphene oxide (rGO) nanosheets enhances the interaction among rGO nanosheets through welding effect, which restricts the slip of rGO nanosheets and the detachment among microspheres, leading to a significant improvement on mechanical properties. The as-prepared carbon aerogel with tightly packaged cell-wall architecture displays ultrahigh compressibility (up to 99% strain) and elasticity (90.1% stress retention and 99.0% height retention after 10000 cycles at 50% strain), which are superior to those of the present bubble-templated carbon aerogels and many other carbon materials through various methods. The structural feature leads to rapid and stable current response and high sensitivity to external strain and pressure, allowing the carbon aerogel to detect very small pressure and various human motions from finger bending to pulse. These advantages make the carbon aerogel promising for flexible electronic devices.