The invention relates to the field of fertilizers and particularly relates to an organic fertilizer. The organic fertilizer is prepared from the following ingredients in parts by weight: 20-25 parts of straws, 10-20 parts of sawdust, 10-12 parts of expansible perlite powder, 1-2 parts of nitrification inhibitor DMPP, 0.3-0.5 part of tea saponin, 50-80 parts of goat manure, 20-35 parts of biogas residue, 10-15 parts of green manure, 20-35 parts of fumigated soil and 5-15 parts of cake meal. According to the organic fertilizer, the disadvantages in the prior art can be overcome, the preparation method is simple, the prepared organic fertilizer is high in utilization ratio, the investment of the conventional fertilizers is reduced, the nitrogen activity is improved, inherent nutrients in soil can be activated, crops can thoroughly absorb and utilize the nutrients, the increase of yield of the crops is promoted, the resistance of the crops is improved, and the soil can be effectively improved; due to high adaptability, the organic fertilizer is applicable to the majority of crops and soil; and due to good compatibility, various fertilizers can be added.