The invention discloses nitrogen-rich hierarchical pore biomass charcoal and application thereof, and belongs to the technical field of environment-friendly functional carbon materials. The inventionaims to solve the problems of low nitrogen content, underdeveloped pore structure and the like of the existing nitrogen-doped biomass charcoal. The preparation method comprises the following steps: putting biomass and carbon nitride into a carbonate aqueous solution, uniformly stirring and mixing, drying, heating a dried material to 800-900 DEG C in an inert atmosphere, calcining, washing a calcined product, and drying to obtain a finished product. Nitrogen-rich carbon nitride is adopted as a nitrogen doping agent, high-nitrogen-content doping is realized, and an activator carbonate is added,so that the pore structure of the biomass charcoal is effectively improved, and the biomass charcoal has good low-temperature hydrogen sulfide removal performance.