The invention relates to an enzyme preparation method. The enzyme is prepared by mixing, fermenting and extracting the following raw materials in parts by weight: 100 to 200 parts of natural organic fruits and vegetables, 100 to 200 parts of traditional Chinese herbals, 5 to 10 parts of clean water, 1 to 30 parts of probiotics, 500 to 2500 parts of edible sugar, and 100 to 400 parts of salt. Specifically, the preparation method comprises the following steps: picking, weighing, and washing natural organic fruits and vegetables and traditional Chinese herbals, drying natural organic fruits and vegetables and traditional Chinese herbals in the air, putting natural organic fruits and vegetables and traditional Chinese herbals into an extraction tank; after all raw materials have been added into the extraction tank, adding clean water, white sugar, salt, and probiotics, evenly mixing; carrying out primary fermentation for 7 to 15 days, naturally extracting a liquid containing effective components, controlling the indoor temperature in a range of 10 to 25 DEG C; filtering to obtain an enzyme primary liquid; delivering the obtained enzyme primary liquid into a tank body in a fermentation aging chamber by a liquid pump through a pipeline, keeping a constant room temperature (25-37 DEG C) of the fermentation aging chamber; and carrying out fermentation aging for 240 to 480 days to obtain the liquid enzyme stock solution.