The invention relates to a biological enzyme preparation. The biological enzyme preparation comprises, by weight, 1.2-1.5 parts of dextranase, 2.5-8 parts of amylase, 1-5.3 parts of lipase, 1.8-4.5 parts of protease, 1.5-3.8 parts of oxidase, 0.8-1.6 parts of glutamine transaminase, 0.5-1.2 parts of phytase, 1.5-5.0 parts of emulgator, 1.0-5.0 parts of water retention agents and 0.5-3.5 parts of flour gluten fortifier. By means of the biological enzyme preparation, the dough performance can be adjusted obviously, the bread size is increased, the bread stiffness is obviously improved, and the bread softness is improved. A preparing method of the biological enzyme preparation includes the steps of weighing the above raw materials by weight to be stirred and evenly mixed, passing through an 80-mesh sieve, further stirring and even mixing until the raw materials are completely and evenly mixed, and obtaining the biological enzyme preparation.