Background: Rapid and reliable diagnostic assays were critical for prevention and control of the coronavirus pneumonia caused by COVID-19. Objective: This study was to establish one-pot real-time reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay and one-pot visual RT-LAMP assay for the detection of COVID-19. Methods: Six specific LAMP primers targeting the N gene of COVID-19 were designed, the RT-LAMP reaction system was optimized with plasmid pUC57 containing N gene sequence, the detection limit was determined with a serial dilution of the plasmid pUC57 containing N gene sequence, and the one-pot real-time RT-LAMP assay and one-pot visual RT-LAMP assay for the detection of COVID-19 were established. Results: Our results showed that the one-pot RT-LAMP assays can detect COVID-19 with a limit of ≥ 6 copies per μl−1 of pUC57 containing N gene sequence. Conclusion: This study provides rapid, reliable and sensitive tools for facilitating preliminary and cost-effective prevention and control of COVID-19.