Poly (N-hexadecyl pyridine acetylenic alcohols bromide)/silver/silver chloride (Pp-16@Ag/AgCl) composite as a novel photocatalyst is fabricated by in situ polymerization of N-hexadecyl pyridinium acetylenic alcohols bromide (p-16) on the surface of Ag/AgCl. The prepared composite photocatalysts were characterized by multiple techniques. The results indicated that Pp-16 layer was formed on the surface of Ag/AgCl, which promoted photoinduced electron-hole pairs separation and endowed the compost catalyst with high phtocatalysis capacity. The phtocatalysis evaluation tests manifested that 99% of Rhodamine B (RhB) and Fast green (FG) were effectively degraded in minutes by Pp-16@Ag/AgCl, while 51% of RhB and 69% of FG Ag/AgCl were depcompoed by Ag/AgCl. The activity of Pp-16@Ag/AgCl was almost kept in four cycles of reutilization. Apart from the dosage of Pp-16@Ag/AgCl and irritation time, pH value of the solution also affected the decomposition efficiency due to the different charge density on the two dyes. The probe of photocatalysis mechanism elaborated that photogenerated hole and superoxide radical were the main active species in the degradation of RhB and FG by Pp-16@Ag/AgCl, and Pp-16 could promote the generation of center dot O-2(-). Therefore, Pp-16@Ag/AgCl demonstrates high catalysis activity under ultraviolet light irradiation.