Abstract: In order to innovate technology of enzyme inactivation，and to improve quality and drying rate of Hemerocallis citrina Baroni，Hemerocallis citrina Baroni of Chenzhou variety was taken as material to determine way and method of enzyme inactivation by comparing endogenous steam and exogenous compressed steam.Results showed that product quality of exogenous compressed steam inactivation were significantly improved and drying rate was increased by 3.5%.The best temperature for enzyme inactivation was 110-115 ℃.Effect of exogenous compression steam inactivation was significant，which should be used to replace traditional endogenous steam inactivation.