The invention discloses a drilling rig for a double-tube high pressure jet grouting technology. The drilling rig comprises a slurry feeding assembly, a drill pipe and a drill bit, wherein the slurry feeding assembly comprises a slurry feeding channel, a first high-pressure slurry feeding core tube, a gas feeding channel and a first gas tube; a second slurry feeding core tube and a second gas tube are arranged in the drill pipe; a drill bushing is arranged at the lower end of the drill pipe; a three-way joint is arranged in the drill bushing; high pressure slurry jetting nozzles are respectively arranged at two outlets of the lower end of the three-way joint; and a gas outlet hole is formed in the lower end of the drill bushing. By the slurry feeding channel and the gas feeding channel, two medium jet streams including high pressure cement slurry and air are ejected out in the transverse direction simultaneously by two tubes, and impact and damage soil, along with rotating, swinging and lifting of the drilling rig, soil damaging energy is increased obviously under combined action of high pressure slurry and surrounding air on the periphery of the high pressure slurry, the slurry and soil particles are forcedly stirred and mixed to form a cylindrical jet-grouted solid after being solidified, the purpose of reinforcing a foundation or stopping water to prevent seepage is achieved, and construction efficiency and pile-forming quality are improved effectively.