Method for comprehensively utilizing rotundine resolution mother liquor

The invention relates to a method for comprehensively utilizing a rotundine resolution mother solution. The method comprises the following steps: reducing fibrauretine into racemic tetrahydropalmatine, resolving the racemic tetrahydropalmatine by using a chiral resolving agent to obtain L-tetrahydropalmatine (namely rotundine), and recycling tetrahydropalmatine (including dextro-tetrahydropalmatine, L-tetrahydropalmatine lost in the resolving process and racemic tetrahydropalmatine which is not completely resolved) from mother liquor after resolving as raw materials. The preparation method comprises the following steps: completely dissolving palmatine in a solvent, carrying out oxidative dehydrogenation under the action of an oxidant to obtain palmatine hydrobromide or palmatine hydriodate, carrying out hydrochloric acid conversion to obtain palmatine or reducing palmatine through a reducing agent to obtain racemic tetrahydropalmatine, and resolving the racemic tetrahydropalmatine through a chiral resolving a