The agglomeration tendency of AgCl, as a photocatalyst, hampers its advancement and practical application. In this paper, a simple composite method is designed based on the precipitation characteristics of AgCl. Ag+ ions introduced from outside combines with Cl− anions in complex [Zn(L)Cl]n (M1) [L = 2-(1-(carboxymethyl)-1H-benzo [d] imidazol-3-ium-3-yl)acetate)] to directly form Zn-MOF/AgCl composites (ZA-x, x = 0.5, 1 and 2), which may effectively prevent agglomeration of AgCl. The morphology and structure analysis displays a remarkable dispersity of AgCl. Further characterization and analysis of PL, UV–Vis, EIS, and TPC reveal that the composites have potential as excellent photocatalysts. The subsequent visible light catalytic degradation of Rhodamine B (RhB) and tetracycline hydrochloride (TC) has shown that the optimal composite ZA-0.5 with M1 to AgCl ratio of 1:0.5 exhibits the highest degradation efficiency in the 20 mg/L solution of RhB or TC, achieving 99.1 % for RhB within 20 min and 81.9 % for TC within 50 min. The free radical trapping test shows that ⋅O2− is the main catalytic species in the degradation process. In addition, the possible degradation mechanism was analyzed by VB-XPS and LC-MS. In a word, the in-situ combination of Cl− in M1 with Ag+ improves the dispersity of AgCl, enhances the interaction between M1 and AgCl, and leads to the effetive separation of electrons and holes, therefore improving the photocatalytic performance.