Broadband light detection and sensing are widely applied in modern technology. As a promising candidate for next-generation two-dimensional (2D) optoelectronic material, bismuth oxyselenide (Bi2O2Se) nanoplates exhibit many prospects in the application of visible light detection due to their peculiar properties. In this work, we report the photodetection performance of single-crystal 2D Bi2O2Se nanoplates grown on SiO2 based on a ternary-alloy growth model by utilizing chemical vapor deposition (CVD). The Bi2O2Se nanoplates were found to have an even and uniform square shape with side lengths up to 15 µm and an approximate thickness of 15 nm. A visible-light photodetector was fabricated based on a CVD-grown Bi2O2Se nanoplate, and characterized by a set of illumination experiments using a 400 nm laser at temperatures ranging from 77 to 370 K. The device exhibited superior performance at the temperature of 77 K, with a responsivity of 523 A/W, a specific detectivity of 1.37 × 1011 Jones, a response time of 0.2175 ms, and an external quantum efficiency of 162,119.44%, resulting in high-quality and full-color imaging in the visible spectrum. These results indicate that the single-crystalline Bi2O2Se nanoplates have excellent potential in broadband photodetection and non-cryogenic imaging.