The invention discloses a composite 
bamboo shoot fermenting agent and a preparation method of fermented 
bamboo shoots. The composite 
bamboo shoot fermenting agent contains 
monascus vinasse and liqueur koji. The preparation method of the fermented 
bamboo shoots comprises the following steps of: firstly, 
blanching bamboo shoots; and then, fermenting the bamboo shoots under the action of the composite 
bamboo shoot fermenting agent. Under the action of the composite bamboo 
shoot fermenting agent, aromatic substances, pigments, and the like in the 
vinasse are infiltrated in the bamboo 
shoot tissues. The prepared 
vinasse-processed bamboo shoots have the characteristics of unique fragrance and 
flavor, mellow and pleasant taste, elegant 
flavor, attractive color and rich 
nutrition. The preparation method can effectively prevent fresh bamboo shoots from aging, lessen the loss of 
nutrient contents, preserve the 
nutrient contents of the bamboo shoots and ensure the quality and the grade of the bamboo shoots. The fermented bamboo shoots prepared by using the method disclosed by the invention have appropriate proportions of liquor, 
sugar and acid, and have the advantages of low 
alcohol and 
sugar contents, stable resistance to acid and alkali, strong 
heat resistance and light resistance, stable resistance to oxidoreduction and favorable practical values and application prospects.