研究二能级原子与双模腔场相互作用系统，考虑双模间存在耦合的情况。采用Negativity熵度量两体系统间的纠缠，具体计算了场模间的耦合系数取不同值时系统中原子熵、原子与场模间纠缠和两场模间纠缠的演化。讨论了场模间的耦合强度变化对纠缠特性的影响。结果表明：原子与场模间纠缠和两场模间纠缠均呈现出周期性演化规律，并且其演化周期随场模间耦合的增强而减小；原子和场模间的纠缠与模间耦合系数之间存在非线性关系，但两场模间纠缠随模间耦合系数增大而减弱。

System of a two-level atom interacting with two-mode cavity is considered in which two modes are coupled. Negativity is used to quantify the degree of entanglement. By means of numerical calculations, the evolution of the entanglement between atom and field or between two modes is investigated. The influence of coupling coefficient between two modes on the entanglement is discussed. The results show that the entanglement between atom and field or that between two modes displays periodic evolution, and its period is decreased with the increase of coupling coefficient between two modes. The entanglement between atom and field has a nonlinear relation with the increase of coupling coefficient between two modes. The entanglement between two modes is weakened with the increase of coupling coefficient between two modes.