The invention relates to a preparation method of a high-strength biomass carbonaceous fuel. The preparation method comprises the following steps: crushing wood flour and peanut shells, drying, then adding a binder and performing extrusion forming by a thermoforming machine, wherein the forming pressure is 15-25Mpa and the forming temperature is 180-230 DEG C; and demolding, then placing into a carbonization furnace for carbonization, placing the prepared carbon fuel into a ZnCl2 solution with the mass fraction of 12%-25% for soaking, and further placing into an activation furnace for activation so as to prepare the high-strength biomass carbonaceous fuel after activation, wherein the activation temperature is 650-800 DEG C. By adopting the preparation method provided by the invention, the strength and density of the biomass carbonaceous fuel are improved, and the biomass carbonaceous fuel further has high calorific value, easiness in ignition, environmental friendliness, high burnout rate, relatively large specific surface area and porosity and strong adsorption performance, and can be widely used in the fields of metallurgy, environmental friendliness and life.