Cu2O/PbWO4 was prepared via a mechanical composite method, demonstrating that polyhedral Cu2O was deposited on coral-like and rod-shaped PbWO4. Cu2O/PbWO4 exhibited superior photoelectric performance compared to Cu2O and PbWO4, reaching a photocurrent and photovoltage reached of 0.0518mA·cm−2 and 0.00133V, respectively. Cu2O/PbWO4 achieved 92.4% and 97.6% tetracycline and doxycycline degradation within 60min under visible light, respectively, and >83% tetracycline degradation continued to be achieved after 5 cycles. The enhanced photocatalytic performance of Cu2O/PbWO4 compared to Cu2O was mainly attributed to the formation of heterojunctions, which increased the charge transfer rate, effectively improving charge lifetime and separation efficiency. The response surface experiments demonstrated that optimal tetracycline degradation (96.4%) could be achieved using 37.5mg·L−1 tetracycline and 18.3mg Cu2O/PbWO4 at a solution pH of 7.1. Four possible tetracycline degradation pathways were proposed and 14 degradation intermediates were detected, which were further degraded into low-molecular-weight substances such as CO2 and H2O through further photocatalytic reactions.