Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia is a newly recognized disease, and its diagnosis is primarily confirmed by routine reverse transcriptase -polymerase chain reaction (RT-PCR) detection of SARS-CoV-2. Methods However, we report a confirmed case of SARS-CoV-2 pneumonia with a negative routine RT-PCR. Results This case was finally diagnosed by nanopore sequencing combined with antibody of SARS-CoV-2. Simultaneously, the ORF and NP gene variations of SARS-CoV-2 were found. Conclusions This case highlighted that false-negative results could be present in routine RT-PCR diagnosis, especially with virus variation. Currently, nanopore pathogen sequencing and antibody detection have been found to be effective in clinical diagnosis. [ABSTRACT FROM AUTHOR]