Abstract: 【Objective】To screen the biocontrol strains with good activity against Meloidogyne incognita and provide a theoretical basis for the development and application of nematicidal agents.【Method】Bacillus was isolated from soil samples collected near the root of cucumber resistant to M. incognita by plate dilution method. Strains with high and stable nematicidal activity were screened by impregnation method. The active strains were classified and identified based on morphological characteristics, physiology and biochemistry and 16S rDNA identification. In vivo, pot and field experiments were conducted to verify the effect of the isolated strain on the control of M. incognita.【Result】A Bacillus C1 with high nematicidal activity was screened, and the strain C1 was identified as Lysinibacillus macrolides. The nematicidal activity results showed that the relative inhibition rate of the fermentation supernatant of strain C1 on the egg hatching of M. incognita was 74.50%, the relative inhibition rate on the female hatching was 95.17%, and the 24 and 48 h corrected mortality of the second-stage juvenile were 98.83% and 100.00%, respectively, with stable nematicidal activity. Pot experiment showed that the control effect of 50 times dilution of fermentation broth of strain C1 on tomato M. incognita was 73.24%. The results of field disease control experiment showed that the control effect of 50 times dilution of C1 fermentation broth on cucumber M. incognita was 82.67%, with yield 20.0% higher than that of clear water control.【Conclusion】Strain C1 not only shows good control effect on M. incognita, but also promotes crop growth. It can be developed and utilized as biological pesticide and fertilizer in agricultural production.