Using the Lactobacillus plantarum 01 (Lp01) and Lactobacillus fermentatum 01(Lf01) as the fermentation strain of pickled potherb mustard， the effects of different lactic acid bacteria inoculation conditions (Lp01 single bacteria， Lf01 single bacteria and Lp01 complex Lf01) on bacterial community structure and volatile flavor compounds of pickled potherb mustard were studied by 16S rDNA sequencing and headspace solid phase microextraction combined with GC. The results showed that the group inoculated with Lp01 combined with Lf01 started quickly， the pH dropped to 4.05 on day5， and the sensory synthesis score of pickled potherb mustard was significantly higher than that of other groups (85.40). Different lactic acid bacteria inoculation had significant effects on the bacterial community structure changes before and after fermentation. The Lf01 single bacteria inoculation group and its complex Lp01 inoculation group immediately multiplied lactic acid bacteria after fermentation for 1 day， and the abundance was significantly higher than other groups， which enriched the microbial diversity. In addition， different lactic acid bacteria inoculation had no significant effect on the total amount of volatile flavor compounds， but the contents of different types of compounds were significantly different. The contents of esters and alcohols in Lf01 single bacteria inoculation group and its compound Lp01 inoculation group were higher than those in Lp01 single bacteria inoculation group and natural fermentation group. ROAV showed that ethyl 2-methylbutyrate， β-lonone， damascenone， 2-methoxy-3-sec-butyl pyrazine and dimethyl trisulfide were the key flavor substances in pickled potherb mustard. Spearman correlation analysis showed that dominant bacteria were positively correlated with many key flavor substances. In conclusion， the single Lf01 inoculation and its complex Lp01 inoculation could improve the bacterial community structure in the early fermentation stage， and many key flavor substances were correlated with the dominant strains.