The invention discloses a biomass hot blast stove and belongs to the technical field of hot blast stoves. The biomass hot blast stove comprises a feeding motor (A), a material barrel (B), a screw feeder (C), a hearth fan (D), a hot air cavity air blower (E), a computer control system (F), a stove body (1), a hot air cavity (2), a hearth (3), a hot air cavity air outlet pipe (4), a heating chamber (5-1), a hot air box (5-2), a hot air outlet (6), a settling pond (7), a chimney (8), a chimney check hole (8-1), a hearth air inlet pipe (9), an ignition bar (10), an ash removing stove door (11), a stove grill (12), a stove door (13), a hot air cavity air inlet pipe (14) and a thermal insulation material (15). A secondary air feeding same-chamber three-dimensional burning mode is adopted, burning is thorough and efficient, tar is avoided, the burning efficiency is high, the heat conversion rate is high, an internal combustion system and an external hot air system are completely independent, automatic control is achieved, and the biomass hot blast stove is free of pollution when used for a long time.