Ni-Ti-O/SiO2 catalyst was prepared by impregnation method, and its photocatalytic performance for carbonylation of methanol with CO2 was investigated under UV light. The in-situ IR, XPS and MS were carried out to analyze the possible photocatalytic reaction mechanism. Results indicated that the Ni-Ti-O/SiO2 exhibited good photocatalytic performance for carbonylation of methanol with CO2, the methanol conversion reached up to 24.9%, and the selectivity for the carbonylated products was more than 60% within 180 min reaction time. The catalyst characterization results showed that the OC·O- and CH3OC(O)· might be important intermediate in the carbonylation of methanol with CO2.