A novel inorganic-organic modified composite coagulant polyaluminum chloride-titanium cationic polyacrylamide(PTA-CPAM) was prepared by chemical reaction with aluminum chloride(PAC), titanium tetrachloride(TiCl₄) and cationic polyacrylamide(CPAM). The infrared spectroscopy, scanning electron microscopy with energy dispersive spectrometer(SEM-EDS) and differential thermal analysis(TG-DTA) were applied to analysis the structural characteristics, composition and thermal stability of the polymer. The coagulation properties of PTA-CPAM was investigated, and the results showed that the better water purification effect of coagulant could be obtained when the mass ratio of CPAM and Al was 2:5, the optimum dosage was 9 mg/L and the pH value was 9.0. Moreover, PTA-CPAM had better turbidity removal ability for water samples with different initial turbidity, and the PTA-CPAM had stronger adsorptive neutralization and adsorption bridging ability due to the synergistic effect, which led to excellent turbidity removal performance.