Development and application of TCM body regulating protection scheme for the convalescent population of novel coronavirus pneumonia (COVID-19)

INTERVENTION: Experimental Group:Xiaotan Sanjiefang granule;Control Group:placebo (contain 5% test drug); CONDITION: Novel Coronavirus Pneumonia (COVID‐19) PRIMARY OUTCOME: Lung CT Score; SECONDARY OUTCOME: COVID‐19 symptom score;Integral evaluation of qi deficiency and phlegm stasis syndrome;Pulmonary function assessment;St George's respiratory questionnaire score; INCLUSION CRITERIA: 1. Meet the history of COVID‐19 confirmed in accordance with the diagnosis and treatment plan of COVID‐19(trial seventh edition); 2. Meet the discharge standards of COVID‐19(trial seventh edition); 3. Meet the diagnosis standard of qi deficiency and phlegm stasis syndrome; 4. Patients aged 18‐70 years old, 28 days after discharge, still have abnormal manifestations on lung CT; 5. Patients willing to sign informed consent.