This is a multicenter, randomized, double-blind, placebo-controlled study to investigate the beneficial efficacy and safety of Chinese medicine formula Modified Qing Zao Jiu Fei Decoction (MQZJFD) on pneumoconiosis patients. Participants will be randomized into one of the two groups (MQZJFD treatment group or placebo control group), and both undergo a consultation process by the Chinese Medicine practitioner (CMP). Eligible participants will be randomized and receive either MQZJFD granules or placebo granules for 16 weeks followed by post-treatment visits at week 20. The study will last for 20 weeks with a treatment period of 16 weeks plus a follow-up period of 4 weeks.