Crude flavonoids were extracted by ultrasonic assisted alcohol extraction. The effects of ultrasonic time, solid-liquid ratio (g∶mL), ethanol mass fraction and ultrasonic power on flavonoids extraction were investigated by single factor experiment and orthogonal experiment. To improve the purity of flavonoids from Ficus hirta vahl by static and dynamic purification with macroporous resin. The effects of macroporous adsorption resin type, mass concentration of crude flavonoids and pH value on static and dynamic purification were investigated. Based on MTT assay, nuclear staining, reactive oxygen species detection and flow cytometry, the inhibitory activity of purified Ficus hirta vahl flavone on HepG2 cells was investigated. The results showed that the optimal extraction conditions of crude flavonoids from the single factor experiment and orthogonal experiment were as follows: Under the conditions of 90 min ultrasonic time, 1∶40 solid-liquid ratio (g∶mL), 80% ethanol mass fraction and 400 W ultrasonic power, the average extraction amount of flavonoids was 5.720±0.713 mg/g, and the purity of crude flavonoids was 6.05%. The macroporous adsorption resin AB-8 showed the best purification performance. The optimal static purification conditions of the crude flavonoids were 0.7408 mg/mL, pH = 4, and the mass fraction of the desorption solution was 60%. The optimal dynamic purification conditions of the crude flavonoids were 0.2408 mg/mL. pH = 4, the loading volume was 65 mL, the mass fraction of eluent was 60%, and the amount of eluent was 40 mL. The purity of flavonoids was increased from 6.05% to 32.67% by dynamic purification of AB-8. AB-8 purified Ficus hirta vahl flavonoid can inhibit the proliferation of HepG2 cells, reduce cell survival rate, and promote cell apoptosis.