Based on the relativistic calculations of the nuclear masses in the transfermium region from No to Ds using the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc), the possible existence of bound nuclei beyond the neutron drip lines is studied. The two-neutron and multi-neutron emission bound nuclei beyond the primary neutron drip line of are predicted in , and isotopes. A detailed microscopic mechanism investigation reveals that nuclear deformation plays a vital role in the existence of bound nuclei beyond the drip line. Furthermore, not only the quadrupole deformation but also the higher orders of deformation are indispensable in the reliable description of the phenomenon of reentrant binding.