The rapid development of the power industry has resulted in a significant amount of electric porcelain solid waste. To address the challenges of small‐scale utilization and low added value associated with the current utilization of porcelain solid waste, a new high‐temperature resistant material was successfully developed using waste electric porcelain with varying particle sizes as the primary raw material. The dependence of composition, structure, and mechanical properties on fine particle size and sintering temperature was explored. The research has determined that the most effective particle size for the synthesis of refractory materials using waste electric porcelain is 120 mesh, and the optimal temperature is 1600°C. When the temperature exceeds 1500°C, the expansion generated by the decomposition of sillimanite will counteract the shrinkage of the liquid phase reaction, thereby maintaining the morphology of the sample. This process forms a unique interwoven mullite morphology through the decomposition of sillimanite, thereby enhancing the strength of the material. As a result, the optimal bending strength of 74 MPa and the optimal compression strength of 207 MPa were obtained. The realization of high‐temperature resistant materials based on discarded electric porcelain has shown foreseeable potential in large‐scale high‐value utilization.