本文针对长方形基坑井群降水采用等距布置井距或凭经验排列造成降水效果欠佳,排水耗能增加这一实际问题,以干扰井群计算理论为依据,建立基坑各不利点的干扰降深方程,提出了确定最佳井距的算法,此法使基坑降水的排水量减少3%,排水耗能降低9%. This paper is based on the practical theory of equidistantly setting the well spacing or empirically arranging the well spacing due to poor precipitation and the increase of drainage energy consumption. Based on the disturbed well group calculation theory, the interference of various disadvantages of the foundation pit is established. The depth reduction equation is proposed and an algorithm for determining the optimal well spacing is proposed. This method reduces the drainage of the foundation pit by 3% and the drainage energy consumption by 9%.