[Objective] To analyze the composition of endosymbiosis microbes of Martianus dermestoides at different stages, we took adult and larva as the research objects. [Methods] By the extraction of endosymbiosis microbes of Martianus dermestoides and high-throughput sequencing analysis, we obtained the composition and changes of microflora in different samples. [Results] At different insect stages, the endosymbiosis microbes abundance and diversity of Martianus dermestoides changed greatly with the development of the insect, the number of bacteria in the adult was relatively small, and the diversity was significantly lower than that in the larva. Different insect states had also significant differences in the composition of several specific microorganisms. Among the adult, Vagococcus and Lactobacillus were dominant bacterial genus; Lactobacillus in larvae was the dominant bacterial genus. The change of fungi was not obvious, and Saccharomyces spp. was dominant. [Conclusion] Our findings provide related information of biotic resources of Martianus dermestoides. Meanwhile, the result can also furnish the theoretical basis for the development and utilization of Martianus dermestoides endosymbiosis microorganism resources.