视频序列运动矢量分布的中心偏移特性在运动估计中发挥重要的作用，但忽视了运动矢量分布的方向性。该文提出了非对称双十字形搜索(UDCS)算法，给出了在搜索的初始阶段使用小十字搜索模型对小的运动矢量搜索并在相继的搜索过程中使用具有方向性的十字形搜索模型对大运动矢量进行搜索的步聚。介绍了该算法的实现结构，并分析了该算法搜索性能。-Video sequence of motion vector distribution characteristics of the center offset is estimated in sports play an important role, but ignored the direction of motion vector distribution. This paper presents asymmetric double cross search (UDCS) algorithm, given the initial stage in the search using small cross english model of small motion vector search and the search process have been using a directional cross english model of large motion vector search步聚. Introduce the realization of the algorithm structure, and analyze the search performance of the algorithm.