[Objective] The effects of Bacillus and a plant growth regulator on the growth and development of moss biocrusts were studied in order to provide a scientific basis for improving the provenance propagation efficiency of moss biocrusts.[Methods] A two-factor complete experiment was designed to observe the coverage, height, and density of moss biocrusts under greenhouse conditions by selecting Bacillus(B. mucilaginosus/B. megaterium) and growth regulator (Thidiazuron, TDZ) as the two variables.[Results] ① The growth status was optimal after the addition of B. mucilaginosus, which increased the coverage (+18.9%), height (+0.85 mm), and density (+15.44 strains/cm) compared to the control group (no Bacillus and growth regulator). ② After the addition of B. megaterium, the density of moss biocrusts increased (+5.76 strains/cm²); however, the height decreased (-0.78 mm) and the coverage was not significantly changed. ③ Treatment with TDZ reduced the coverage (-11.78%) and height (-3.33 mm); however, it had no significant effect on the density of moss biocrusts. ④ The growth status of BSC was significantly affected by the interaction of Bacillus and TDZ. The combination treatment of B. megaterium and TDZ increased the density of moss biocrusts (+9.79 strains/cm²) and was higher than that of the treatment where only B. megaterium was added (+3.67 strains/cm²). Additionally, the combined treatment of B. mucilaginosus and TDZ increased the density of moss biocrusts (+4.3 strains/cm²); however, it weakened the positive effect of B. mucilaginosus (-11.14 strains/cm²).[Conclusion] The effects of functional microorganisms and a growth regulator on the growth and development of moss biocrusts are very significant, which should be considered during the practice of provenance propagation of moss biocrusts.