In this work, BiOCl modified titanium phosphate nanoplates (BiOCl/TP) composite photocatalysts with p-n heterojunctions were prepared by a in-situ growth method. The morphology, crystal structure and optical properties of the prepared samples were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectrometry (DRS). Rhodamine B (RhB), reactive brilliant Red X-3B (X-3B), methylene blue (MB), ciprofloxacin (CIP) and phenol were used to investigate the photocatalytic performance of the prepared samples under ultraviolet light irradiation. Results showed that the BiOCl/TP exhibited much higher activity for the degradation of all these model organic pollutants than pure TP. The mechanism for the enhancement of the photocatalytic performance was established with the help of the results of photocurrent measurements and Photoluminescence spectra. The results illustrated that the enhanced activity could be attributed to the formation of p-n heterojunctions between p-type BiOCl and n-type titanium phosphate, which effectively suppressed the recombination of photo-induced electron-hole pairs. Furthermore, the possible photocatalytic mechanisms on the degradation of the organic pollutants were also proposed.