In order to overcome the disadvantages of difficult recycling, equipment corrosion and environmental pollution, perovskite oxides with abundant acid-base active sites were selected to catalyze n-valeraldehyde self-condensation. The catalysts were characterized by XRD, SEM, NH3-TPD and CO2-TPD. Combined with the activity evaluation, the influences of catalyst preparation conditions and reaction conditions were investigated, and the interaction between acid and base active sites was clarified. The results show that pure phase CaTiO3 with better dispersion and catalytic performance can be obtained by sol-gel method under the optimal condition: a dosage of dispersant polyethylene glycol (PEG-1000) = 2.5%(benchmarked against the quality of calcium nitrate, the following is the same), calcined at 500 ℃ for 1 h. The suitable n-valeraldehyde self-condensation conditions catalyzed by CaTiO3 were determined as follows: a reaction temperature of 190 ℃, a reaction time of 8 h and a weight percentage of catalyst = 15% (benchmarked against the quality of n-valeraldehyde, the following is the same). Under the above conditions, the conversion of n-valeraldehyde and the selectivity of 2-propyl-2-heptenal reached 97.0% and 99.1% separately. After being reused for four times, the catalytic performance of CaTiO3 had no significant decrease. NH3 and CO2 were used as probe molecules to selectively poison the active sites of CaTiO3 catalysts, respectively, and the results indicate that there is an obvious synergistic catalysis between the acid and base active sites.