本文应用熵最大原理，假定腔内二能级原子起初就没有关于系统所处态的任何信息，研究了腔内原子与腔场相互作用的压缩行为，得出了原子初始处于任意统计混合态下，当初始激发足够强时，辐射场将产生极其接近于纯态情况在相同激发时的强压缩现象的重要结果，同时还讨论了产生压缩的混态范围.

In this report, the information about the initial saute of a two-level system in a cavity is supposed to have nothing by using the principle of maximal entropy. The squeezing behavior of a two-level atom interaction with the cavity field are studied. We have obtained an important result that the strong squeezing of the radiation field, when the atom stunS initially in an arbitrary statistical mixed state and initial exciting of the field is intensive enough, is close to those very much that the atom lies in a pure state initially. In the same time, the mixed-state limits of squeezing occurring are discussed.