Objective: To optimize technique of preparing baicalin solid lipid nanoparticles (BC-SLN) by film-ultrasonic wave dissolving techniques. Methods: The influence of various factors, including the dosage of baicalin, stearic acid, lecithin and tween 80 on the entrapment efficiency were investigated. And the optimum formula was selected through orthogonal design test. Results: 20 mg baicalin, 90 mg stearic acid, 90 mg lecithin and 10 ml tween-80 (2.5%) for the technique. The products had good size distributions. The mean particle size diameter was 289.3 nm, and the average entrapment efficiency was 67.17%. Conclusion: The technique of preparing BC-SLN by film-ultrasonic wave dissolving technique is feasible.