The invention discloses a plastic electric-spraying throttle valve body assembly, comprising a throttle valve body (1), a throttle valve spindle (2), a throttle valve piece (3), a torsion spring (4), a swing frame (5), a position sensor (6), a stepping motor (7), a flange plate metal insert (10), an idle screw mounting hole metal insert (11), stepping motor and position sensor mounting hole metal inserts (12), a card (14) and an idle adjusting screw (17), wherein a main channel (8) and an idle side channel (9) are arranged inside the throttle valve body (1), and a base of the throttle valve body (1) is provided with a flange plate (18). The plastic electric-spraying throttle valve body assembly has the beneficial effects that the defect of easy deformation of the main channel of the plastic throttle valve body can be effectively overcome, the fast interchange of a metal throttle valve body assembly and a plastic throttle valve body assembly in the process of assembly and after-sale maintenance of an engine is realized, and the leak problem of the side channel of the throttle valve body caused by different coefficients of thermal expansion is solved.