【Objective】 Previous studies have shown that Bacillus cereus NJSZ-13 strain has the best effect on Pinus massoniana growth. To further analyze and evaluate the underlying biological and control mechanism of the strain on Bursaphelenchus xylophilus, NJSZ-13 strain was added to the insect and egg liquid to study the killing effect of the strain on B. xylophilus and its oviposition, egg hatching and reproduction activities.【Method】 NJSZ-13 strain was divided into suspension, fermentation broth and fermentation filtrate by centrifugation, and then mixed into the original solution, with 5, 10, 100 and 1 000 dilutions. The concentrations of suspension and fermentation broth were 3×10 ⁸ cfu/ mL, and sterile water and NB medium were used as the control. ①The nematocidal effects of NJSZ-13 strain on B. xylophilus in 24 and 48 hours were determined by the immersion method. ②Ten pairs of female and male fourth instar larvae with good growth were selected and placed in a 1.5 mL centrifuge tube. After being treated with NJSZ-13 strain for 24 h, the eggs were washed from the centrifuge tubes into 35 mm culture dishes, and the amounts of eggs laid in each treatment counted. ③Sterile egg solutions (1 mL, containing about 400 eggs) and NJSZ-13 strains were placed into 35 mm dishes for the counting of the numbers of hatched worms at 12, 24 and 36 h. ④The mixtures of nematode solution (100 μL) (containing 500 B. xylophilus) and 100 μL NJSZ-13 strains were put into 60 mm culture dishes of Botrytis cinerea. The nematodes were isolated and counted using the behrmann method after being cultured in a 25 ℃ incubator for five days. 【Result】 ①The nematocidal rate of NJSZ-13 was 100% after 24 h of treatment, while the killing rate of NJSZ-13 strain was only 81.47% after 48 h of treatment. ②NJSZ-13 strain could inhibit the oviposition of B. xylophilus significantly, and the inhibition decreased with an increase in dilution ratio. ③The 10-fold dilution of the NJSZ-13 strain inhibited the hatching of the eggs significantly at 12 h, with a significant level achieved at 24 h, only the fermentation broth and fermentation filtrate exhibited significant inhibition at 36 h. When treated with the 100-dilution for 12 h, the fermentation broth and fermentation filtrate had significant differences when compared with the control, with no significant differences at the other treatment time points. ④ There were significant differences in fecundity between NJSZ-13 strain and the control group (P < 0.05). When 10-dilution solution was used to treat B. xylophilus, the bacterial suspension had no significant effect on B. xylophilus fecundity.【Conclusion】 Bacillus cereus NJSZ-13 strain had nematocidal effects on B. xylophilus. Among them, the nematocidal effects of fermentation broth and fermentation filtrate were more significant; NJSZ-13 strain could inhibit B. xylophilus oviposition, egg hatching and reproduction, and the inhibitory effects of fermentation broth and fermentation filtrate were more obvious than those of the bacterial suspension.