The invention discloses a microorganism-enzyme powdery composite biological preparation for promoting crop yield increase. The composite biological preparation is composed of, by weight, 30% of multiple microbial agents, 21% of multiple biological enzyme preparations, 25% of a microbial nutritional agent, 7% of seaweed, 3% of Fucus plant active ingredients, 3% of sodium humate, 2% of mordenite, 2% of dolomite and the balance moisture. The invention provides the microorganism-enzyme composite biological preparation for promoting high quality and high yield production of crops, and the composite biological preparation is formed by compounding of pure natural preferred strains and a variety of biological enzymes. Integrating the advantages of inoculants and enzyme preparations, the composite biological preparation has the functions of improving the soil structure, antagonizing soil pathogenic bacteria, fixing nitrogen, and dissolving phosphorus and potassium, releases iron, magnesium, manganese, zinc, sulfur, boron, calcium, silicon and a variety of medium trace elements in soil, balances absorption of nitrogen, phosphorus and potassium, removes fertilizer damage, secretes a variety of bioactive substances, enhances crop stress resistance, and can reach the effects of enhancing the yield and quality of crops.