Abstract: Coal gangue is firstly processed by activation when producing silicon fertilizer from coal gangue. By adding promoters and using high temperature calicination method, it was found out that for efficient silicon activation, the optimal scale of promoters for coal gangue: CaCO₃: Na2CO₃: Na2OH was 1: 0.1: 0.5: 0.05, the optimal temperature for coal gangue activation was 700 ℃, the optimal calicination duration was 2 h and optimal size was 80 mesh. According to calicination test, the technology for producing fertilizer from coal gangue was put forward. The teste of composition and hazardous elements verified that the fertilizer produced by experiment was in accordanced with state standards for silicon fertilizer.