【Objective】 Chlorpyrifos residue poses a significant challenge to food safety. Microbial degradation which is called bioaugmentation is an effective approach for the elimination of such residues. Bioaugmentation often involves an invasion process requiring the establishment and activity of a foreign microbe in the resident community of the target environment. Interactions with resident micro-organisms, either antagonistic or cooperative, are believed to impact invasion. However, few studies have examined how the interactions between the invaded degrading bacteria and resident microorganisms in the target environment can influence microbial degradation. In this study, chlorpyrifos-degrading bacteria Shingopyxis granuli CP-2 was used as material, from the perspective of microbe-microbe interactions, to select resident bacterial helper of CP-2. 【Method】 Soils from the field were first collected, a batch of bacteria from the soil was isolated by continuous dilution method, and identified by full-length sequencing of the 16S rRNA gene. The 16S rRNA gene sequences of all isolates were aligned using MUSCLE. Sequences in the alignment were trimmed at both ends to obtain maximum overlap using the MEGA X software, which was also used to construct taxonomic cladograms. A maximum-likelihood (ML) tree was constructed, using a general time reversible (GTR) + G + I model, which yielded the best fit to our data set. Bootstrapping was carried out with 100 replicates retaining gaps. A taxonomic cladogram was created using the EVOLVIEW web tool (https: //evolgenius.info//evolview-v2/). The taxonomic status (phylum) of each rhizobacterial strain was also added as heatmap rings to the outer circle of the tree. The resident bacterial helper which could promote the growth of CP-2 was then screened by supernatant assay from the isolates isolated from soils, and the bioinformatics results of these helpers were analyzed. At last, a bacterial isolate which well promoted the growth of CP-2 was chosen, and its effect on CP-2's ability to degrade chlorpyrifos was investigated in vitro. 【Result】 109 strains of indigenous bacteria were isolated and were classified into four main phyla: Proteobacteria (54.1%), Actinobacteria (14.8%), Firmicutes (15.6%), and Bacteroidetes (15.6%). Among them, 41.3% significantly inhibited the growth of CP-2, 17.4% had no significant effect on CP-2, and 41.3% (45 bacterial strains) significantly enhanced CP-2's growth and were identified as indigenous bacterial helpers of CP-2. The 45 bacterial strains in the helper bank mainly belong to 3 phyla, 4 classes, 7 orders, 13 families and 20 genera. One strain (B72), which exhibited a strong growth-promoting effect on CP-2 was selected to assess its impact on chlorpyrifos degradation by CP-2. The results demonstrated that both the bacterial strain B72 and its supernatant significantly promoted the chlorpyrifos degrading ability of CP-2. 【Conclusion】 Together, the strains identified in this study provide valuable resources for future research and applications involving microbial degradation of soil toxicants such as chlorpyrifos or other pollutants. Furthermore, the indigenous bacterial helper of chlorpyrifos degrading bacterium CP-2 significantly promoted its ability to degrade chlorpyrifos, which offers theoretical guidance and technical support for potential co-inoculation strategies involving both chlorpyrifos-degrading bacteria and indigenous bacterial helpers aimed at pollution remediation.