Cut-off device of flow baffle and method

The invention provides a cut-off device of a flow baffle and a method. The flow baffle is arranged at the downstream position of a cut-off closure gap, the width of the flow baffle does not exceed that of the cut-off closure gap, the downstream position of the flow baffle is hinged to a twist seat fixedly arranged at the river bottom, and a hydraulic jack is arranged below the flow baffle. When the cut-off closure gap is closed to be close to the range of the flow baffle, the hydraulic jack is started to support the flow baffle. The flow speed and fall of the cut-off closure gap are reduced by means of the above steps. By means of the flow baffle structure arranged at the downstream position of the cut-off closure gap, in the high-difficulty cut-off constructing process, cut-off materials are effectively prevented from running off, the cut-off fall of the cut-off closure gap is reduced, the flow speed of the cut-off closure gap is decreased, the cut-off difficulty is reduced, the cut-off safety and success ra