The invention relates to the field of aero-engines and gas steam turbines, in particular to a technique for efficiently machining floating wall tile blocks of a flame tube. The technique comprises thesteps of manufacturing semifinished combination blocks, and carrying out cutting and forming; in the step of manufacturing the semifinished combination blocks, tile block blanks are subjected machining treatment so that the semifinished combination blocks are prepared, at least two convex blocks having the same boundary dimension as the finished tile blocks are arranged on the semifinished combination blocks, a plurality of bulged parts are arranged on the convex blocks, and a plurality of mixing holes are formed in the convex blocks; and in the step of carrying out the cutting and forming, the semifinished combination blocks are cut, the convex blocks are separated from the semifinished combination blocks, and independent semifinished tile blocks are obtained. The multiple floating walltile blocks can be prepared by one-time machining, the machining precision and position precision of the bulged parts on the floating wall tile blocks are relatively high, the preparation cycle of thefloating wall tile blocks is shortened, the production efficiency is improved and the technical problems existing in an original floating wall tile block monoblock casting method are solved.