[Objective] To optimize the ultrasonic extraction process for extracting flavonoids from Bambusa Rigida leaves.[Method] Effect of solvent kind,alcohol concentration,extraction temperature,solid to liquid ratio and extraction time on extraction efficiency of flavonoids were investigated through single factor experiments and the extraction technology was optimized by orthogonal test.[Result] The factors influencing extraction of flavonoids with ultrasonic power at 600 W were in order as follows:alcohol concentration > extraction temperature > ratio of solid-to-liquid ratio > extraction time.The optimal extraction conditions were:alcohol concentration of 85%,extraction temperature of 75 ℃,extraction time of 90 min and solid to liquid ratio of 1∶30.Under this condition,the content of flavonoids from Bambusa Rigida leaves was 11.78 mg/g.[Conclusion] The optimal technology for extracting flavonoids from Bambusa Rigida leaves had obtained in this work,which provided references for industrial production of bamboo leaf flavonoids. [Objective] To optimize the ultrasonic extraction process for extracting flavonoids from Bambusa Rigida leaves. [Method] Effect of solvent kind, alcohol concentration, extraction temperature, solid to liquid ratio and extraction time on extraction efficiency of flavonoids were investigated through single factor experiments and the extraction influencing the extraction of flavonoids with ultrasonic power at 600 W were in order as follows: alcohol concentration> extraction temperature> ratio of solid-to-liquid ratio> extraction time. optimal Extraction conditions were: alcohol concentration of 85%, extraction temperature of 75 ° C, extraction time of 90 min and solid to liquid ratio of 1:30. Under this condition, the content of flavonoids from Bambusa Rigida leaves was 11.78 mg / g. [ Conclusion] The optimal technology for extracting flavonoids from Bambusa Rigida leaves had obtained in this work, which provided references for industr ial production of bamboo leaf flavonoids.