The invention discloses a third main group element modified ruthenium titanium compound oxide and a preparation method and an application thereof and belongs to the technical field of catalytic materials. The preparation method comprises the following steps: first, preparing a titanium oxide catalyst carrier modified by third main group elements with different molar contents by means of a sol-gelmethod; and then loading ruthenium by means of an impregnating method to prepare the compound oxide. Titanium salt used by the sol-gel method is titanium sulfate, tetraisopropyl titanate or tetrabutyltitanate, and the used third main group element salt is borate, aluminate, gallium salt or indium salt. The catalyst for chlorohydrocarbon catalytic combustion is low in ignition temperature, and lowin complete combustion temperature. In conditions that the air speed is 60000 ml/g/h and the chlorohydrocarbon concentration is 1000 ppm, the chlorohydrocarbon can be fully combusted at a temperatureof lower than 350 DEG C. Meanwhile, the catalyst also has very high stability, and can be activated for 100 hour at 305 DEG C in catalytic combustion of dichloromethane. The preparation method of thecatalyst is simple and easy to operate, and the prepared catalyst has activity and stability.