Bamboo cellulose fiber (BCF) were degraded by three microbial strategies, pure Brevibacillus brevi (BB), microflora carried by BCF (HM) and a combination of BB and HM (HBB). The enzyme production and degradation functions of different strategies were investigated by shaking flask fementations. The BCF’s structure and microbial community composition of optimal treatment group at different stages during degradation were analyzed, which were assisted by the viscosity method in cupri-ethylene-diamine, XRD, FTIR and 16S rRNA high-throughput sequencing technologies. The results indicated that under the three microbial strategies, BCF showed a certain degradation effects, which dry matter loss rate were 41.92%, 60.74% and 77.65%, respectively, when the fermentation was finished. Compared with BB and HM groups, HBB systerm showed the main degrading period’s highest CMCase and laccase activity, as well as abundant xylanase activity. Early acquisition of structural characteristics, such as the substrate’s size reduced sharply, carbohydrate-lignin linkages destroyed and removed, as well as the defect in crystallization zone, was of benefit to the availability of enzymatic hydrolysis, which was an important reason for BCF’s degradation effectively and speedily. Bacterial species of HBB covered 18 phyla, 26 classes,64 orders, 97 families, 170 genera. Firmicutes, Proteobacteria, as well as Bacteroidota, Actinobacteriota,Verrucomicrobiota were the dominant phyla in HBB. There were significant differences between the main and late degrading periods in microbial species and relative abundance at genus level. Devosia, Ochrobactrum, Taibaiella, Brevundimonas had a relatively high relative abundance in the main degrading period than that of in the late stage, while Pseudoxanthomona, Cohnella, unclassified_o_Flavobacteriales were relatively abundant in the late degrading stage. PCoA and ANOSIM analysis at phylum and genera levels indicated that there were differences in community structure of HBB samples obtained from the two typical degrading periods, but no statistical signigicance. The results showed that HBB could accelerate the degradation of BCF and obtain a relatively high dry matter loss rate compared with BB or HM alone. HBB showed a certain stability and reliability during degrading. Brevibacillus、Devosia, Ochrobactrum, Taibaiella, Pseudoxanthomona, Azospirillum, Cellulomonas were the main functional species of HBB for BCF degradation in efficiency.