The present invention provides an invisible light flat plate detector and a manufacturing method thereof, an imaging apparatus, relates to the field of detection technology, can solve problems that the structure of the invisible light flat plate detector in the prior art is complex and the manufacturing method thereof is tedious. The invisible light flat plate detector of the present invention comprises a plurality of detection units and an invisible light conversion layer provided above the detection units for converting invisible light into visible light, each of the detection units comprising a thin film transistor provided on a substrate, and a first insulation layer, a first electrode, a semiconductor photoelectronic conversion module, a second electrode which are successively provided above the thin film transistor and of which projections on the substrate at least partially overlap with a projection of the thin film transistor on the substrate.