In light of the construction process of the RJP method, the hydraulic system of XLT[CD*2]230 high-pressure rotary jet rig is designed to include the following main hydraulic circuits: the power head rotation circuit, which can realize continuous switching between forward and reverse rotation for swing jetting of RJP method; the power head lifting and lowering circuit, which can realize fast/slow lifting and lowering of the power head, and intermittent step-lifting function as well; the drilling rig travel circuit, which can provide for travel stability without deviation; and the auxiliary action circuit to ensure the stability and reliability of auxiliary action. The field construction test showed that the hydraulic system of the drilling rig is properly designed with high reliability and good energy-saving, fully meeting the construction requirements of RJP method.