The invented cervical vertebrae front-path steel plate bone screw locking device relates to a kind of cervical vertebrae front-path steel plate and its fixing component, suitable for curing the diseases of cervical vertebrae regression, wound and tumor, etc. Its structure possesses butterfly steel plate and bone screw, said bone screw can be assembled into the bone screw hole on the butterfly steel plate, and it is characterized by that on the butterfly steel plate a locking plate seat hole is set at the place closed to bone screw, locking plate seat is placed in the locking plate seat hole, on the locking plate seat the locking plate assembling recess is set, the locking plate is mounted on the recess, and the upper portion of bone screw can be covered by two wings of the locking plate, and on the locking plate the locking hole and open groove are set.