Abstract： Objective： To discuss the effect of Radix Astragali injection on apoptosis of lung cancer cells and phosphatidylinositol- 3- kinase/protein kinase B(PI3K/AKT) signaling pathway. Methods： A549 cells at logarithmic growth phase and in a good condition were selected and randomly divided into the control group，the Experiment Group 1，and the Experiment Group 2. The control group was cultured in a routine medium for intervention； the Experiment Group 1 was intervened with 100 mg/mL Radix Astragali injection based on the intervention of the control group；the Experiment Group 2 was intervened with 200 mg/mL Radix Astragali injection based on the intervention of the control group. MTT method was used to detect cell proliferation. Double staining method was used to detect apoptosis index. Transwell assay was used to detect cell migration. Western-blot method was used to detect the expression of protein of PI3K/AKT. Flow cytometry was used to detect cell cycle. Results：After intervention for 24 h and 48 h，in the Experiment Group 1 and the Experiment Group 2， indexes of cell proliferation， migration distances， and the relative expression levels of protein of PI3K and AKT were decreased when compared with those in the control group(P＜0.05)，and apoptosis indexes were increased(P＜0.05). After intervention for 24 h and 48 h，in the Experiment Group 2，index of cell proliferation，migration distance，and the relative expression levels of protein of PI3K and AKT were lower than those in the Experiment Group 1(P＜0.05)，and apoptosis index was higher than that in the Experiment Group 1(P＜0.05). After intervention for 48 h， in the Experiment Group 1 and the Experiment Group 2，the proportions of G0/G1 phase were decreased when compared with those in the control group(P＜ 0.05)， and the proportions of S phase and G2/M phase were increased(P＜0.05). After intervention for 48 h， in the Experiment Group 2， the proportion of G0/G1 phase was smaller than that in the Experiment Group 1(P＜0.05)， and the proportions of S phase and G2/M phases were larger than those in the Experiment Group 2(P＜0.05). Conclusion： Radix Astragali injection can inhibit the activation of PI3K/AKT signaling pathway in lung cancer cells and have an effect on normal cell cycle，thus promoting apoptosis and inhibiting proliferation and migration of cells.