The invention relates to a sun-cured yellow tobacco leaf seal-yellowing technology and adjusting processing method. The seal-yellowing technology includes using a gunny bag sheet as an isolation layer to perform seal-yellowing treatment on acquired tobacco leaves. The preparing processing method includes the seal-yellowing technology. High-quality seal-yellowed adjusted sun-cured yellow tobacco leaves can be acquired through the method. The gunny bag sheet is used as the isolation layer, seal-yellowing of the tobacco leaves can be achieved in short time, the problem that the tobacco leaves cannot be dried due to bad weather can be solved, human resources and material resources can be saved, the quality of the tobacco leaves can be improved, and the demand of the cigarette industry for high-quality sun-cured yellow tobacco can be met.