A new guidance mode named over-the-shoulder unitary guidance mode was studied on the basis of high off-boresight guidance law in view of the difficulty of attacking target with high off-boresight launching as well as attacking the target at the back. This guidance mode could extend application range and avoid a series of problems brought by the hand-off process. The results of simulation indicate that this guidance law, which is suitable for dogfight missile, could control the missile to turn rapidly and hit the target near ideal impact with little miss distance, and improve lethality of high off-boresight launching.