The invention discloses an expansion tube expansion technological method and a tool system, and belongs to the technical field of drilling well completion in the petroleum and gas industry. The tool system comprises a lifting sub, a center rod assembly, a connecting rod assembly, an expansion tube assembly, a connecting short section, an expansion cone assembly, a combined hydraulic cylinder, a hydraulic anchor and a screwed plug. A thread is arranged on the upper portion of the lifting sub, the lifting sub is connected with a drill rod, and thus a novel expansion tool string can be tripped into a preset position. The lower end of the lifting sub is connected with the center rod assembly, the center rod assembly is formed by three same center rods in a threaded connection mode, expansible stopping blocks are arranged on each center rod at intervals, and the stopping blocks are pre-arranged in an expansion tube after compression. When the center rods are lifted up, the stopping blocks can be ejected automatically when being exposed out of the expansion tube, and the stopping blocks can be fixed at the end of the expansion tube when the center rods are moved to the stopping blocks. The stopping blocks are expansible through a spring mechanism, four sets of the stopping blocks are arranged altogether, and the stopping blocks are evenly distributed on the circumference of each center rod. By means of the expansion tube expansion technological method and the tool system, well drilling cost and well completion cost are lowered, and thus a wide application prospect can be achieved.