||This study introduces the innovative method of in-situ precipitation (ISP) 3D printing technology for fabricating photocatalyst structures capable of efficiently degrading water pollutants. The technology involves using silver nitrate aqueous solution to print directly on the surface of solidified NaBr aqueous solution, resulting in the formation of regular porous silver bromide structures. The structures are then densified through drying and sintering, followed by photoreduction using ultraviolet radiation to create Ag@(silver atom cluster)AgBr photocatalyst structures. Experimental results demonstrate the effectiveness of this photocatalyst structure in degrading azo dyes (Orange II) and eliminating Escherichia coli (E. coli) under visible light and ultraviolet light irradiation. The degradation of azo dyes and the sterilization of E. coli follow first-order kinetic reactions, with the photocatalyst module maintaining an 84.8% degradation rate after five recycling cycles. Complete elimination E. coli of the photocatalytic module is achieved within 120 min, and its sterilization effect follows a hyperbolic reaction. The study further confirms the durability and reusability of the photocatalyst structure, highlighting ISP 3D printing technology as a promising approach for fabricating efficient photocatalyst structures to address water pollution challenges in water treatment and environmental protection.