The development of multifunctional silicone foam with high fire safety is of great significance to realize intelligent fire protection but challenging. Herein, a multifunctional ceramifiable fire-retardant silicone foam (MCSF) was fabricated by Ti3C2Tx nanosheet (MXene), multiwalled carbon nanotube (MWCNT), γ-aminopropyltriethoxysilane (APTES), Karstedt catalyst (Pt) and vinyl dimethylsiloxane via water–oil interface induced self-assembly and dehydrogenation foaming at room temperature. MCSF possessed low density and good mechanical properties. Its improved thermoelectric performance and sensitive fire-warning capability of MCSF were attributed to the skeleton supporting effect and unique electron transport effect between MWCNT and MXene. When being burned, MCSF was able to trigger the fire-warning system within 2.4 s and repeatedly alarm the fire reignition. Furthermore, owing to the synergism between APTES and Pt, MCSF exhibited good ceramization performance. When encountered high temperature, the MCSF surface rapidly ceramized, generating a ceramic-like barrier layer to block the further flame ablation, and it quickly self-extinguished after removing from flame. Besides, MCSF showed impressive thermal insulation and durable piezoresistive sensing. This work provides a new strategy for the preparation and application of multifunctional fireproof polymer foams.