The invention discloses a nano preparation for pulmonary fibrosis and a preparation method thereof, namely a nano preparation modified with protease with mucin degradation and a carrier of the nano preparation. The preparation method comprises the steps that firstly, the nano preparation is responsively released by virtue of the property of mucin degradation of the protease, and then therapeutic drugs are efficiently delivered to a pulmonary fibrosis injury part, so that efficient targeted delivery of anti-pulmonary fibrosis drugs is realized, and the purpose of efficiently treating the pulmonary fibrosis is achieved. Aiming at the problem that deep delivery difficulty generally exists in currently marketed tracheal and inhaled administration dosage forms, that is, a large number of drugsare difficult to deliver to the deep alveoli to come into play due to excessive secretion of mucus by goblet cells in a trachea, the change of the excessive secretion of the mucus in a pulmonary fibrosis trachea microenvironment is adopted, and the nano preparation which is responsively released and can efficiently pass through a trachea barrier is constructed, so that the therapeutic drugs are efficiently delivered to the pulmonary fibrotic injury part in the deep alveoli, and the efficiency of the nano preparation reaching the deep alveoli is improved.