Background Autophagy has always been a current research hotspot during lung cancer treatment. Purpose This study aimed to explore the molecular mechanism by which cucurbitacins loaded in liposome nanoparticles (Cu B-NPs) inhibit the development of lung cancer through Beclin 1 (BECN1) regulation. Methods Cu B-NPs were prepared, and the A549 group, Cu B group, and Cu B-NPs group were set up to assess the mechanism of Cu B-NPs in regulating autophagy and inhibiting the development of lung cancer. Cu B-NPs+si-BECN1 group and Cu B-NPs+pc-BECN1 group were also set up to analyze whether Cu B-NPs regulate autophagy through BECN1 to inhibit the development of lung cancer. Results Cu B-NPs were successfully prepared and had good dispersion stability. Cu B-NPs reduced cell viability, promoted apoptosis and the accumulation of autophagosomes, and regulated apoptosis-related proteins, thereby inhibiting lung cancer development. After activating/inhibiting BECN1 expression, Cu B-NPs promoted cell autophagy and apoptosis by upregulating BECN1 expression, thereby inhibiting the development of lung cancer. Conclusion In this study, Cu B-NPs were successfully prepared, and the particles promoted autophagy and induced apoptosis in A549 cells by upregulating BECN1, thereby inhibiting the development of lung cancer. This provides strong evidence and clues for further research and development of lung cancer treatment strategies.