A brush head apparatus of a multifunctional oral care tool comprises a pair of transmission rods (5) respectively connected with a pair of brush heads (1). The pair of brush heads (1) are integrally formed by using a food-grade silica gel type of soft material respectively. The pair of brush heads (1) respectively performs a 360-degree rotation in opposite directions. A back of the pair of brush heads (1) is provided with a back-flushing plate (4). An end portion of the transmission rods (5) is lower than an end portion of the brush heads (1). A top portion of the back-flushing plate (4) is lower than a top portion of the brush heads (1).