The invention provides a soil improvement type straw compound organic fertilizer and a preparation method of the soil improvement type straw compound organic fertilizer. The soil improvement type straw compound organic fertilizer is prepared from the following raw materials in parts by weight: 30 to 35 parts of rice straw, 25 to 30 parts of animal excrement, 20 to 25 parts of biological charcoal, 10 to 15 parts of soybean meal, 5 to 10 parts of cassava residue, 5 to 10 parts of diatom ooze, 2 to 2.5 parts of plant ash, 2 to 2.5 parts of turfy soil, 2 to 3 parts of zeolite powder, 3 to 4 parts of a microorganism bacterium agent, 2 to 3 parts of sodium benzoate, 2 to 3 parts of ammonium monohydrogen phosphate, 1 to 2 parts of calcium chloride, 1 to 2 parts of amino acid, 1 to 2 parts of starch, 1 to 2 parts of molasses powder and 1 to 2 parts of humic acid. The soil improvement type straw compound organic fertilizer takes plant wastes as raw materials; the quality of soil can be easily improved and the production cost can also be reduced, so that the physicochemical properties of the soil are improved, and the structure of the soil is comprehensively improved, and furthermore, the soil quality has the effects of softness, air permeability, water retention and fertilizer conservation; the aim of producing an environment-friendly high-quality organic fertilizer through preferably selecting heavy metal capable of being passivated, the biological charcoal capable of improving the fertilizer efficiency of the organic fertilizer, and conversion products of organic wastes including the biological humic acid and the like as composting base materials, and optimizing a composting process.