A channel baffle structure for a HTR nuclear power plant, comprising a pipe, a swing check plate and a driving apparatus: the swing check plate comprises a tongue plate, a crank connecting rod and a rotating shaft, one end of the crank connecting rod is connected with the tongue plate through a nut, and the other end of the crank connecting rod is welded to a shaft sleeve of the rotating shaft; the pipe wall of the pipe is provided with a circular opening for placing the tongue plate in a fully open state and the crank connecting rod, a circular branch pipe is welded at the circular opening, an axis of the circular branch pipe is perpendicular to an axis of the pipe, an end of the circular branch pipe is in a form of flange structure and connected with a pipe side cover plate by bolts; the tongue plate, the crank connecting rod and a part of the rotating shaft of the swing check plate are arranged within the pipe, the driving apparatus is arranged outside the pipe; the swing check plate and the driving apparatus are connected through the rotating shaft, a bevel gear and a driving apparatus connecting shaft; one end of the rotating shaft is connected with the swing check plate, and the other end is connected with the bevel gear; one end of the driving apparatus connecting shaft is connected with the bevel gear, and the other end is connected with the driving apparatus; wherein a structure for connecting the driving apparatus and the swing check plate, comprises a key installed on the rotating shaft connected with the crank connecting rod, an annular keyway correspondingly set within the shaft sleeve of the rotating shaft, such that the shaft sleeve has an idle travel of 90-degree free rotation around the rotating shaft, and the key is positioned within the annular keyway. the swing check plate comprises a tongue plate, a crank connecting rod and a rotating shaft, one end of the crank connecting rod is connected with the tongue plate through a nut, and the other end of the crank connecting rod is welded to a shaft sleeve of the rotating shaft; the pipe wall of the pipe is provided with a circular opening for placing the tongue plate in a fully open state and the crank connecting rod, a circular branch pipe is welded at the circular opening, an axis of the circular branch pipe is perpendicular to an axis of the pipe, an end of the circular branch pipe is in a form of flange structure and connected with a pipe side cover plate by bolts; the tongue plate, the crank connecting rod and a part of the rotating shaft of the swing check plate are arranged within the pipe, the driving apparatus is arranged outside the pipe; the swing check plate and the driving apparatus are connected through the rotating shaft, a bevel gear and a driving apparatus connecting shaft; one end of the rotating shaft is connected with the swing check plate, and the other end is connected with the bevel gear; one end of the driving apparatus connecting shaft is connected with the bevel gear, and the other end is connected with the driving apparatus; wherein a structure for connecting the driving apparatus and the swing check plate, comprises a key installed on the rotating shaft connected with the crank connecting rod, an annular keyway correspondingly set within the shaft sleeve of the rotating shaft, such that the shaft sleeve has an idle travel of 90-degree free rotation around the rotating shaft, and the key is positioned within the annular keyway.