The invention provides a medicament composition for treating pulmonary fibrosis. The medicament composition comprises the following active pharmaceutical ingredients by weight: 5-15 parts of ginseng, 5-15 parts of danshen root, 1-11 parts of angelica, 5-15 parts of manyflower solomonseal rhizome, 5-15 parts of perilla frutescens, 1-11 parts of brassica alba boiss, 1-11 parts of fructus aurantii immaturus and 5-15 parts of Japanese ardisia herb. The invention also provides a preparation method of the composition and application of the composition to preparing the medicaments for treating pulmonary fibrosis. The chemical fiber No.1 medicament composition provided by the invention has the effect of inhibiting proliferation of human embryo lung diploid fibroblasts (2BS), can be used for preparing the medicaments for treating pulmonary fibrosis, has obvious clinical effect, minimal side effect and good safety and provides a new choice for clinically treating pulmonary fibrosis.