The invention belongs to the technical field of preparation of slow-release fertilizers and particularly relates to a method for preparing an organic-inorganic composite controlled-release fertilizer by using straw organic embedding materials and functional bacteria and a product therefrom. The method is characterized in that organic embedding materials are prepared from straws, and biochar brings in major and minor elements and the like to serve as envelopes of inner and outer layers, so that organic matters and fertilizer components react to generate stable complexes; and functional bacteria, livestock and poultry excrements and the like required for different growth periods are brought in for compounding, and multi-layer wrapping is performed to form the organic-inorganic composite slow-release fertilizer with functional bacteria. The slow-release fertilizer provided by the invention can effectively prevent the drawbacks of soil structure destruction and environmental pollution caused by fertilizer use and maintain the continuous balanced nutrient supply.