The fabrication and characterization of GaN-based 512×1 ultraviolet linear photodetector are reported in this work. AlGaN multilayers are grown in wetel-organic chemical vapor deposition (MOCVD). Material etching,passivation,metal contact and other techniques are used in the manufacture of 256×1 back-illuminated AlGaN detector. The current-voltage (I-V) curve shows that current at zero bias is 4.22×10^-12A and resistance is 1.01×10¹⁰Ω. A flat band spectral response is achieved in the 305-365 nm. The detector displays an unbiased responsivity of 0.12 A/W at 359 nm. This detector is bonded to a readout circuit with capacitive feedback transimpedance amplifier (CTIA) structure. Two modules are put together to form 512 linear ultraviolet focal plane arrays (FPA). The FPA is measured in 300 K and achieved average voltage responsivity 1.8×10⁸ V/W,the blind rate 9.0% and the response nonuniformities 17.8%. The measurement of signal and noise led to a detectivity of 7×10¹⁰cmHz^1/2W^-1 at 359 nm.