This article aims to explore the combined detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin M (IgM)/immunoglobulin G (IgG), viral nucleic acid and interleukin 6 (IL-6) in the diagnosis and treatment of coronavirus disease in 2019 (COVID-19). This study collected 93 patients (51 critical, 18 severe, 15 mild and 9 normal) according to the standard of “New Coronavirus Pneumonia Diagnosis and Treatment Plan (Version 7)” and 20 suspected cases (negative nucleic acid test but clinical symptoms and Ct test results met the standards). 110 patients with other diseases such as pediatrics, gynecology, tumors, blood and digestion illness were selected as the control group. Automatic chemiluminescence immunoassay technology and electrochemiluminescence technology was used to detect 2019-nCoV IgM/IgG and IL-6 in the serum of all subjects. Real-time fluorescence quantitative reverse transcription polymerase chain reaction was used to detect SARS-CoV-2 nucleic acid in pharyngeal swabs of case group and control group. The results showed that the positive rates of serum IgM, IgG and IL-6 in suspected cases were 85%, 75% and 0%, respectively, and the positive rates in patients diagnosed with 2019 coronavirus were 98.9%, 95.7% and 75.2%, respectively (Among them, critical cases are 100%, 100% and 100%, severe cases are 94.4%, 100% and 97.9%, mild cases are 100%, 93.3% and 5%, and common types are 100%, 66.7% and 0%). The changes of IL-6 and 2019-nCoV IgM/IgG expression levels were related to the severity of the patients' disease, and the differences were statistically significant (χ²＝273.51, χ²＝149.37; P<0.05). The combined detection of serum IL-6 and 2019-nCoV IgM/IgG can be used as a monitoring indicator for the diagnosis and treatment of new coronavirus infection, and can also be used as an effective complement to the false negative detection of SARS-CoV-2 nucleic acid.