非连续变形分析（discontinuous deformation analysis，DDA）方法在处理非连续变形问题中具有显著的优越性，但由于需要处理接触并进行开闭迭代，计算量较大。为了提高DDA方法中接触查找部分的计算效率，并保持较高的精确度，通过改变距离准则下的接触查找方式，提出了改进的接触查找算法。在接触查找前增加预判，减少需要判断的角点数目，并区分两种类型的角-边接触，将对这两种角-边接触的查找分配到不同循环体中，改造了距离准则下的接触查找逻辑。通过两个计算模型来验证改进后程序的准确性和高效性，模型1用来检验程序在各种接触条件下的计算结果，计算结果表明，改进后的程序精确度可以满足；模型2采用东河口滑坡模型，计算结果表明，在保证计算结果精度的前提下，改进后程序的计算效率可提高10%左右。

Discontinuous deformation analysis (DDA) method benefit greatly in discontinuous deformation problems, whereas contact disposing and open-close iteration used in DDA cost significant amount of time. In order to improve the computational efficiency of the contact searching in the DDA method and maintain high accuracy, an improved contact searching algorithm is developed by changing the contact searching mode within the distance criterion. By increasing the pre-judgment, the number of corner points that need to be determined are reduced before contact searching. Two types of angular-edge contacts are distinguished and the search of these two angular-edge contacts is assigned to different loops, which changes the contact searching logic under the distance criterion. Two computational models verify the accuracy and efficiency of the improved program. Model 1 is used to test the program under various contact conditions with improved accuracy. Model 2 is employed to calculate the Donghekou landslide with improved efficiency of about 10% under the premise of guaranteeing the accuracy of the calculation results.