The invention discloses an uncooled infrared focal plane detector photoelectric sensitive unit, and aims at providing an uncooled infrared focal plane detector photoelectric sensitive unit which is high in measurement resolution and high in sensitivity. The uncooled infrared focal plane detector photoelectric sensitive unit comprises a resonant cavity which is formed by a semitransparent metal layer, an organic dielectric layer and a reflecting metal layer through superposition, and a detector unit which is fixedly arranged below the resonant cavity and used for realizing photoelectric signal conversion. At least one of the semitransparent metal layer, the organic dielectric layer and the reflecting metal layer of the resonant cavity is provided with pierced lines and/or patterns. The corresponding layers of the resonant cavity are pierced so that thermal crosstalk of the resonant cavity can be effectively reduced and spatial resolution of the detector unit can be enhanced.