The present invention discloses a package structure of a MEMS microphone. The package structure comprises a closed inner cavity formed by a package shell in a surrounding manner, as well as a MEMS chip and an ASIC chip which are located in the closed inner cavity, wherein a sound hole allowing sound to flow into the closed inner cavity is formed in the package shell; the MEMS chip comprises a substrate as well as a vibrating diaphragm and a back plate which are provided on the substrate; the vibrating diaphragm divides the closed inner cavity into a front cavity and a back cavity; and a sound-absorbing structure is provided in the back cavity.