Objective To investigate the regulatory effect of wingless gene 7a (Wnt7a) on Bacille Calmette Guerin (BCG) induced autophagy in alveolar epithelial cells. Methods The alveolar epithelial cells of TC-1 mice were treated with interfering Wnt7a lentivirus and BCG alone or together in four groups, namely, small interfering RNA control (si-NC) group, si-NC combined with BCG group, Wnt7a small interfering RNA (si-Wnt7a) group, and si-Wnt7a combined with BCG group. The expressions of Wnt7a, microtubule associated protein 1 light chain 3 (LC3), P62, and autophagy related gene 5 (ATG5) were detected by Western blot analysis, and the distribution of LC3 was detected by immunofluorescence cytochemical staining. Results Compared with those in the si-NC group, Wnt7a, ATG5 and LC3 expressions increased and green fluorescent spots of LC3 significantly increased in the BCG infected TC-1 cells; the expressions of Wnt7a, LC3, P62, and ATG5 and green fluorescent spots of LC3 significantly decreased in the si-Wnt7a combined with BCG group comparing with those in the si-NC combined with BCG group. Conclusion Knocking down Wnt7a inhibits BCG induced autophagy in mouse alveolar epithelial cells.