We developed a hollow PEGylated encapsulin nanoparticle from Rhodococcus erythropolis N771. The hollow engineered encapsulin nanoparticles with His-Tag and Lys residues on the surface were constructed by means of genetic recombination. The Lys residues on the particle surface were successfully PEGylated with a PEG derivative, methoxy-PEG-SCM. Consequently, we demonstrated that the hollow PEGylated engineered encapsulin nanoparticle could successfully disassemble or reassemble even after PEGylation in the presence or absence of a protein denaturing agent. The nanoparticle obtained in the present study has the potential to incorporate hydrophilic compounds in the internal cavity of the particle by reversibly controllable disassembly and reassembly. The hollow PEGylated encapsulin nanoparticle can be used as a drug carrier for the delivery of hydrophilic biopolymers in future medical applications.