Abstract: The pipe string of producing method with layer by layer was designed according to the problem that efficiency of mechanical water plugging and success ratio is low in moderate-high water cut stage in field development. Using two types switch matching with packer examination and sealing by itself, the sealing property of the packer testing and the status of on-off of the switch testing of this pipe string were implemented with once pipe. This can achieve separate layer recovery layer by layer and oil prospecting water plugging. The structure, technology theory and parameter of this pipe were introduced. By 35 wells field testing, the efficiency is 94.3% and the adding up increase productivity is 16290 t.