The invention discloses a compound microorganism live bacteria preparation for degrading papermaking wastewater COD, a preparation method and applications thereof. The preparation contains Penicillium decumbens, Myrothecium Verrucaria, Bacillus massiliensis and a solid fermentation medium. The preparation method comprises the following steps: first, Penicillium decumbens and Myrothecium Verrucaria after inclined plane activation are inoculated in a liquid medium respectively, and cultured at the temperature of 25 DEG C -30 DEG C for 44-52 h to obtain a microorganism bacteria liquid; Bacillus massiliensis after inclined plane activation is inoculated in a liquid medium, and cultured at the temperature of 28 DEG C-37 DEG C for 40-52 h to obtain a microorganism bacteria liquid; second, the microorganism bacteria liquids are mixed uniformly, placed in a solid fermentation medium and fermented and cultured at the temperature of 30 DEG C for 40-80 h, and the processes of drying at the temperature of 40 DEG C-60 DEG C, crushing to 15-50 meshes and sieving are performed. The preparation can degrade papermaking wastewater COD effectively, rapidly and efficiently in applications as a COD-degrading enhancer in the papermaking wastewater treatment process. The preparation can improve wastewater chromaticity and water quality.