The application value of solar-blind ultraviolet photodetector is significant in fields such as military, communication, medical treatment, and environmental monitoring. Developing self-powered detectors is key to addressing the reliance on external bias voltage and high energy consumption of traditional devices. In this study, high-quality β-Ga₂O₃ thin films were prepared via plasma-enhanced chemical vapor deposition and combined with spin-coated PEDOT:PSS polymer to construct an organic–inorganic van der Waals heterojunction self-powered solar-blind photodetector. Its photoelectric performance and potential for single-pixel imaging applications were systematically investigated. Characterization results show that the prepared β-Ga₂O₃ thin film exhibits good crystallinity and a smooth surface, with selective absorption in the solar-blind ultraviolet region and a bandgap of approximately 4.92 eV. Under zero bias voltage and illumination at 254 nm with an intensity of 47 μW/cm², the detector achieves a photo-to-dark current ratio of 8.8 × 10³, a responsivity of 0.106 A/W, and an external quantum efficiency of 38%. The photocurrent exhibits a near-linear dependence on light intensity. The device operates stably under both positive and negative bias, with low dark current, minimal noise, and excellent weak-light detection capability.Using a fixed-step point-by-point scanning method, the detector successfully achieved single-pixel solar-blind ultraviolet optical imaging of the letters "IMU", demonstrating good imaging quality and high fidelity. The heterojunction detector developed in this study combines the advantages of self-powered operation, simple structure, and low cost, overcoming the limitations of traditional materials used in single-pixel imaging. It provides a new strategy for advancing solar-blind ultraviolet detection technology and shows promising practical potential in the field of single-pixel optical imaging.