OBJECTIVE To optimize the pr eparation technology of the baicalin lipid nano foam aerosol （BC-LN-FA）. METHODS Baicalin lipid nanoparticle （BC-LN）and BC-LN-FA were prepared by the thin film dispersion method and homogeneous emulsification method ，respectively，using baicalin （BC） as the model drug. The preparation technology was optimized by Box-Behnken design-response surface methodology using particle size and encapsulation efficiency （EE）as indexes ，with dosage ， emulsifier dosage ，co-emulsifier dosage and homogenization time as factors. The morphology ，particle size ，polymerdispersity index（PDI），EE，the viscosity ，the foam dissolution rate and in vitro transdermal release of BC-LN-FA were characterized. RESULTS The optimal technology included 25 mg BC ，40 mg emulsifier （mass ratio of stearic acid-soybean lecithin-glycerol was 1∶1∶1），30 mg co-emulsifier （mass ratio of octadecanol-lactic acid was 1∶1），homogenization time of 20 min. Results of 3 times of validation tests showed that particle size of prepared BC-LN-FA was （151.70±2.40）nm，EE was （68.62±1.16）％；the deviation of them from the predicted value （particle size of 150.80 nm，EE of 67.02％）were 0.60％ and 2.39％ respectively. The BC-LN-FA prepared by the optimal process was light yellow opalescence ，uniform in particle size and round-like in shape. The viscosity，the foam dissolution rate ，the content of BC and PDI were （122.92±5.09）mPa·s，（65.32±3.22）％，（7.01±0.12）％ and（0.199±0.006），respectively. At 48 h，the cumulative release rates of BC-LN-FA in phosphate buffer saline （PBS）at pH 7.4， 6.8，5.0 were（54.12±2.69）％，（57.85±4.25）％ and（59.47±1.83）％，respectively；those of free BC in PBS at pH 7.4 was only （15.04±1.43）％. CONCLUSIONS The optimized technology is stable and feasible. Prepared BC-LN-FA has a uniform particle size，high digestion rate and certain viscosity.