In recent years, with the rapid growth of the traditional 
edible fungus industry all over China, the 
pollution and the 
hazard generated to the entironment and the 
edible fungus industry per se by a large number of obsolete 
fungus sticks (slags) after the primary planting of edible fungi also become bigger and bigger, and the innocent treatment and the 
research development in the aspect of reutilization on the obsolete 
fungus sticks in the industry also become more and more, wherein the research of preparing the 
biomass fuel by taking the obsolete 
fungus sticks is an important research direction. The invention provides a method for preparing the 
biomass fuel by taking the obsolete fungus sticks and the fungus slags of the edible fungi as the main materials; the method has low cost and belongs to the field of waste comprehensive development and deep utilization. In the invention, the obsolete fungus sticks and the fungus slags of the edible fungi are used as the main materials, wherein the weight proportion is higher than 50 percent; the mixture ratio of other auxiliary materials is simple and varied and most of auxiliary materials is 
crop wastes; then the main ingredients and the auxiliary materials are extruded to be formed and then dried, thereby preparing the 
biomass fuel. In the invention, the biomass fuel can be processed into products with different density and shapes by adopting common biomass fuel forming equipment in the market. The products of the invention have 
high heat value and do not have 
smoke or stink; under the simple conditions, common peasant households can prepare and use the biomass fuel on the spot; the biomass fuel is a novel environment-friendly fuel. In the 
edible fungus scale planting areas, waste utilization is effectively realized, and 
pollution sources can be thoroughly eliminated.