The invention discloses an ultraviolet avalanche photodiode detector. Each device unit of the detector comprises a CE electrode, an SiO2 layer, a P-well or N-well, a substrate and a back surface electrode in sequence from top to bottom, wherein a point-shaped avalanche photodiode is arranged at the center of the upper part of the P-well or N-well; the point-shaped avalanche photodiode is electrically communicated with the CE electrode; a ground connector GND is peripherally arranged at the periphery of the SiO2 layer. The ultraviolet avalanche photodiode detector is manufactured by adopting a wide band gap semiconductor material, an avalanche region is separated from a photon collection region, and an avalanche multiplication nodal region is relatively small, so that a device with relatively low avalanche voltage can be manufactured, and the uniformity and controllability of an electric field of the avalanche region are good; while an avalanche multiplication high-field region is relatively small, a large-area optical detection region is guaranteed, so that the quantum efficiency is improved; the area of the avalanche region is reduced, and dark current and dark excitation are easy to reduce; meanwhile, the tolerance to the quality and defects of a wafer is improved, and breakdown of the large-area avalanche multiplication high-field region at a defect position is prevented in advance.