The invention discloses an organic-inorganic composite day-blind type ultraviolet light detector which comprises a quartz substrate, a transparent metal electrode layer, an electrode modified layer, an organic-inorganic composite active layer, a cathode modified layer and a metal electrode layer. The transparent metal electrode layer, the electrode modified layer, the organic-inorganic composite active layer, the cathode modified layer and the metal electrode layer are sequentially arranged from bottom to top on the quartz substrate. The organic-inorganic composite active layer is a mixed layer of an organic donor material D and an inorganic acceptor material A or is a layer formed by an organic donor material D layer and an inorganic acceptor material A layer in a stacked mode. A molecular structure general formula of the organic donor material D can be found in the specification, wherein R is pyridine, pyrazine, pyrimidine, pyridazine, triazine and triazole. According to the organic-inorganic composite day-blind type ultraviolet light detector, the carrier transfer ability of the organic donor material with an ultra wide band gap can be improved, a selective response to radiation under 300nm is achieved, and the phenomenon that radiation under 300nm is absorbed by a common ITO substrate is greatly avoided.