[Aim] The objective of this study is to establish a rapid diagnostic method for three species of root-knot nematode attacking plants based on the loop-mediated isothermal amplification (LAMP). This could provide technical support for monitoring and preventing the root-knot nematode infestation.[Method] The DNA fragments of the selected root-knot nematodes were amplified by PCR using species-specific primers of the three root-knot nematodes. The amplified products were purified, recovered and sequenced. Based on the sequencing results of the three root-knot nematodes, three primers were designed using PrimerExplorerV4 software for species-specific segments. The designed primer sets were artificially synthesized, and the purified primer population DNA was used as a template to test the specificity of the primer sets. The best primer sets for three root-knot nematodes were selected.[Result] The LAMP-specific primers of the three root-knot nematodes could directly detect the three common root-knot nematodes from the roots of plants, LAMP rapid detection system included 1 mmol·L^-1dNTPS, 5 mmol·L^-1 Mg²⁺, without betaine, and at a reaction time of 45 min. The rapid detection of Meloidogyne incognita, Meloidogyne arenaria, Meloidogyne javanica by LAMP was assembled.[Conclusion] The method was highly specific, sensitive, and economical, which made it possible for quick and accurate detection of M.incognita, M.arenaria and M.javanica from the infected plant root tissues, with high actual application value.