The invention relates to the technical field of water closets, in particular to a wash-down type water closet flushing structure which comprises a water closet body, a water tank, a side flushing water way, a booster pump and a jet pump. By adopting the series-connection design of the booster pump and the jet pump, the outlet flow rate of the booster pump is improved, so that on the premise of meeting the requirement of the flushing intensity, the demands on the flushing speed and the flow rate required by a wash-down type water closet can be met by adopting the booster pump with low power, the power consumption is reduced, and the wash-down type water closet flushing structure is applicable to the design of a low-level water tank.