In this work, the Br functional group on the ligand UiO-66-Br was modified with a Bi-O bond through the secondary solvothermal method, and the synthesis method of visible light catalyst UB (UiO-66-BiOBr) with high electron mobility was explored. The findings indicate that the effective charge transfer of the functional group-modified material UB is 2.98 times and 1.22 times that of BiOBr and traditional UiO-66/BiOBr heterojunctions, respectively. Under simulated sunlight irradiation, the removal rate of tetracycline can reach 88.71%, and the photocatalytic performance is 22.73 times higher than that of UiO-66-Br. Moreover, it maintains good adsorption and photocatalytic performance under different laboratory and actual engineering water environment conditions. In the complex water environment of municipal wastewater, the degradation effect reaches more than 80%. Finally, the decomposition pathways of TC and ecotoxicities of the intermediates were analyzed via combining theoretical calculation, LC-MS/MS, and T.E.S.T.