When a high velocity vehicle reenters the atmosphere，its surface is Surrounded by a plasma sheath with high temperature. In the region of a certain altitude，the communication between the vehicle and the ground will be discontinued，which is the problem of communication discontinuity in reentry. Some methods to diminish discontinuity have been tested abroad; each of them has its advantages and disadvantages.This paper discusses the possibility to，diminish electronic density in the plasma sheath by using electric field. It is expected to be a simpler physic method for overcoming the communication discontinuity in reentry.