A carrier device and a placement machine, where the carrier device includes a body and a positioner. A positioning sucker mechanism is disposed on the body, and a sliding sucker mechanism is slidably disposed on the body, where the sliding sucker mechanism includes a sucker group, a positioning block connected to one end of the sucker group, and a first suction piece provided on the positioning block. The positioner is arranged on one side of the body and adjacent to the positioning block, and includes a driver and a clamping assembly connected to the driver, where the clamping assembly is provided with a second suction piece mutually attracted to the first suction piece.