The paper aims to research the effect of enzymolysis condition on yield rate and stability of compound juice based on juice yield, light transmittance, total anthocyanin content and DPPH free radical scavenging rate with black garlic and black medlar as the main ingredients. Ratio of cellulose to pectinase, enzyme concentration, hydrolysis temperature and hydrolysis time were selected as the optimal conditions for enzymatic hydrolysis for orthogonal experiment of 4 factors and 3 levels. The results showed that the order of influence on the indexes of the compound juice was enzyme concentration > hydrolysis temperature > reaction time > enzyme ratio. The optimal conditions for enzymatic hydrolysis were cellulase: pectinase mass ratio 2︰1, compound enzyme mass fraction of 0.06%, enzymatic hydrolysis temperature of 50 ℃, and enzymatic hydrolysis time of 3 h. Under this optimized process condition, the juice yield was 91.04%, the light transmittance was 77.27%, the anthocyanin content in the juice was 167.11 mg/L and the DPPH free radical scavenging rate was 58.81%. The compound juice produced by this process has high juice yield rate and high antioxidant activity.