Abstract: An electric engine braking device comprising a control mechanism and an electric driving mechanism, wherein the control mechanism comprises a housing, an execution plunger and a sliding assembly; the sliding assembly comprises a sliding block, a first elastic piece, a transfer plunger and a second elastic piece; the transfer plunger comprises a first position which is completely provided in the sliding block and a second position which extends out of the sliding block to connect the sliding block and the housing into a whole; and the electric driving mechanism comprises an execution motor, a sliding plate frame, a sliding plate and a contact leaf spring, the execution motor can push the sliding plate to slide along the sliding plate frame, drive the contact leaf spring to push the execution plunger to slide, and drive the transfer plunger to move and keep the transfer plunger at the second position.