The invention discloses a single-cylinder drive selective channel device of a multiported valve, which comprises a cylinder (1), a graduator (2), bolts (22), a multiported valve tumbler (3) and a valve plug shaft (31). The single cylinder is adopted for driving, the graduator provided with a plurality of index plunger holes is fixed on the multiported valve, when the single-cylinder drive selective channel device is in work, the bolts are inserted into the index plunger holes for limiting a corner of the multiported valve tumbler to select the number of channels of pipes communicated by the multiported valve, therefore, the invention overcomes the problems and the defects of high cost, large failure rate and complex operation, realizes that one cylinder is used for driving to select the channels by the graduator, and ensures that a gas chromatographic analyzer achieves the purposes of lowering the cost, reducing failures and simplifying the operations.