A back-flushing plate (4) of a multifunctional oral care tool. The back-flushing plate (4) is provided at a back end of brush heads (1), and has an end portion lower than an end portion of the brush heads (1). A pair of brush heads (1) is driven to rotate by a pair of transmission rods (5), such that the brush heads produce a powerful suction flow, and water sucked up splashes onto the back-flushing plate to produce a powerful flush flow, thereby flushing away oral waste. The present invention addresses a problem of deep cleaning of a coated tongue, and also addresses a problem in which tooth-brushing foam and waste liquid remain in an oral cavity.
