The invention discloses a dual-wall drill pipe drilling system and a drilling method. The system mainly consists of a gas phase insertion device, a liquid phase injection device, a rotating control head, a blowout preventer group, a rotating fluid injection device, a dual-wall drill pipe, a dual-wall drill collar, a measurement while drilling device, a gas-liquid convergent flow short section, a power drill and a drill check valve drill bit, wherein a gas phase and a liquid phase flow through the respective passages in front of the measurement while drilling device, and respectively pass through the measurement while drilling device; and after flowing through the measurement while drilling device, the gas phase and the liquid phase are mixed in the position of the liquid-gas convergent flow short section, and finally enter a drilling annular space from a drill bit. The liquid phase transmits the pulse generated by a measuring device to a wellhead for detection through a measuring inner pipe of the measurement while drilling device. The method can solve the problem of difficulty in gas drilling measurement while drilling or well logging in a deep well or a horizontal well, and has wide market application prospects.