The invention provides an environment-friendly stemming and a preparation method thereof. The environment-friendly stemming is prepared from, by mass, 15-40% of aluminum containing aggregates, 2-15% of coke, 1-5% of graphite, 10-25% of silicon carbide, 5-20% of ferro-silicon nitride, 5-20% of aluminum containing fine powder, 5-15% of clay, 2-8 parts of sericite, 2-6% of high-temperature pitch, 2-15% of an expanding agent and a binding agent accounting for the total mass of the other materials by 15-30%, wherein thermoplastic phenolic resin serves as the binding agent. The environment-friendly stemming and the preparation method thereof have advantages that toxic gases are avoided, a furnace front operation environment is improved, environmental friendliness, low raw material consumption, high hardening speed and short sintering time are realized, opening performance and slag iron erosion resistance of the anhydrous stemming are improved, resistance of the anhydrous stemming to flushing and abrasion of high-temperature molten iron is enhanced, and quality stability of the anhydrous stemming is improved.