The present application, pertaining to the field of slow neutron detection, relates to a slow neutron converter and a slow neutron detector. The slow neutron converter includes a substrate, the substrate including a plurality of holes extending along a first direction and insulating walls between the plurality of holes, wherein the plurality of holes are through holes. The slow neutron converter further includes a boron layer at least covering an exposed surface of the plurality of holes. The slow neutron converter and the slow neutron detector having the slow neutron converter according to the present disclosure are capable of maintaining a high slow neutron detection efficiency. In addition, the manufacturing complexity and manufacturing cost of the detector are reduced, and thus the effective, convenient and low-cost slow neutron detection is achieved.