Stable coronary artery disease (SCAD) is a common clinical style in patients with coronary artery disease. Inflammation and immune injury in SCAD have been proven. Current interventions can relieve patients' symptoms, but none are stable to improve the immune damage significantly. Chinese herb is used to treat stable angina pectoris as an alternative therapy. Taoren Honghua Jian granule (THJG) is a classical formula from which patients can benefit, but lack convincing evidence. Therefore, we report a protocol of high-quality randomized controlled trial. We will conduct a randomized, double-blind, placebo-controlled clinical trial to assess the effect of THJG in relief of symptoms and blood immune indexes. A total of 80 patients with SCAD will be enrolled, and treated with THJG or placebo for 4 weeks. The primary outcome measurement is change of integral traditional Chinese medicine (TCM) syndrome score from baseline to 4 weeks' treatment. The 2nd outcome measurements include change of integral TCM syndrome scores from baseline to 2 weeks' treatment and another 4 weeks' follow-up, inflammation indexes at baseline and 4 weeks' treatment. It also includes Seattle Angina Questionnaire, major adverse cardiovascular events, Athens Insomnia scale, and 36-item short form health survey score from baseline to 2 weeks' and 4 weeks' treatment, and another 4 weeks' follow-up. Adverse events will be evaluated throughout the trial. The results of this trial will prove whether THJG could alleviate symptoms, control inflammation, and improve quality of life in patients with SCAD. ChiCTR1900021772, registered 8 March, 2019.