The invention relates to a straw smoldering and rapid humification combined use method and a humic fertilizer product of straws. The combined use method specifically comprises the following steps: (1) crushing the straws, thereby obtaining straw powder; (2) putting part of the straw powder serving as smoldering straw powder into a smoldering furnace, and feeding air for smoldering, thereby obtaining smoldered ash and hot flue gas; (3) uniformly mixing the other part of the straw powder, which serves as a humic fertilizer raw material, with the smoldered ash and an auxiliary material, and putting the mixture into a humification reactor; (4) mixing the hot flue gas with the air, and feeding the hot flue gas and air mixture into the humification reactor to enable the humic fertilizer raw material to be rapidly humified, thereby obtaining the humic fertilizer product. Compared with the prior art, the straw smoldering and rapid humification combined use method has the advantages that the straws which are crops are subjected to smoldering and rapid humification for combined use, and the smoldered ash and the hot flue gas which are produced in the smoldering process are fully used in a rapid humification process, so that rapid and efficient in-situ harmless use of the straws is realized, the environmental pollution is low, and the resource utilization rate is high.