The present invention discloses a coal gangue ceramicite and its preparation method. It is comprises (wt%) 75-85% of coal gangue powder, 5-10% of adhesive, 0-5% of additive and 5-10% of flyash expansion solidifying agent mixture, and its preparation method incldues the following steps: selecitng material, grinding, mixing materials, stirring, making pellet, drying, sintering and sorting, in whichthe described selected material is powdered coal gangue, and its preheaitng drying temp. is 200-600 deg.C, a its sintering temp. is 1.50-1200 deg.C. The invented coal gangue ceramicite possesses highstrength, light weight, low thermal coductivity, high refractoriness and other advantages, can be used in concrete, ceramcite hollow block, reinforced concrete, floor brick and other applications.