The invention discloses a three-layer insertion pipe mechanical water exploration and plugging method and a water exploration and plugging pipe column. A well completion pipe column in the water exploration and plugging pipe column comprises an oil pumping pump, a first sealing insertion pipe, a second sealing insertion pipe, a screening pipe, a third sealing insertion pipe and a fourth sealing insertion pipe which are arranged from top to bottom and are communicated with one another through connection pipes, wherein when the well completion pipe column is lifted or dropped, sealing insertion pipes of the four sealing insertion pipes, which move to positions where two packers are positioned, are matched with central pipes of the corresponding packers in a sealed manner, so that two oil layers on the upper sides and the lower sides of the packers are packed and partitioned; when the well completion pipe column is lifted or dropped to adjust the position of the screening pipe and the communicating states of the oil layers by changing position relations between the four sealing insertion pipes and the two packers; and an oil pump works to exploit the oil layer on which the screening pipe is positioned and the oil layer communicated with the oil layer on which the screening pipe is positioned. By the water exploration and plugging method and the pipe column with a simple structure, three-stage sealing for the oil layers can be realized, and a scheduled layer of a target layer can be exploited.