The invention relates to a biomass hard carbon negative electrode material for a sodium ion battery, a preparing method and the sodium ion battery and belongs to the technical field of sodium ion energy storage equipment. The biomass hard carbon negative electrode material is prepared through the method including the following steps that firstly, a biomass raw material is smashed, and precursor particles are obtained; secondly, in a protection atmosphere, the precursor particles are heated to 400-600 DEG C to be pre-sintered for 1.5-2.5 h, then cooled to the room temperature along with a furnace, then heated to 800-1600 DEG C to be sintered for 2-5 h and cooled, and an intermediate is obtained; thirdly, the intermediate is put into an alkali solution to be soaked, taken out, then put into an acid solution to be soaked, then washed with water to be neutral and dried, and a purified product is obtained; fourthly, the purified product is subjected to microwave vacuum activation for 3-15 s at the power of 1000-2000 W, and then the biomass hard carbon negative electrode material is obtained. The first-time charging and discharging efficiency of the obtained biomass hard carbon negative electrode material reaches up to 90% or above, the circulation stability is good, the reversible specific capacity is 300 mAh / g or above, and the biomass hard carbon negative electrode material has a good electrochemical property.