The invention discloses a method for determining the pile spacing of anti-liquefying vibrating-impacting crushed-stone piles. The method comprises the following steps of 1, judging the liquefied degree of foundation soil according to an in-situ test, wherein one or several methods in a, a critical standard penetration number method, b, a static sounding judging method and c, a shear-wave velocity method is or are adopted by the liquefaction judging method of the foundation soil; 2, determining the dry density needing to be reached by the foundation soil among the piles for eliminating liquefaction; 3, determining the pile spacing of the crushed-stone piles. According to the contrastive analysis of the on-site in-situ testing, the indoor test and the finite-element numerical-value analyzing results of the foundation soil before and after driving the crushed-stone piles, the anti-liquefying efficacy of the vibrating-impacting crushed-stone piles is comprehensive studied, and the method for determining the pile spacing of the crushed-stone piles is provided on the basis and on the basis of a compaction effect, so that pile-testing projects are omitted, the construction period is shortened, and the construction cost of the projects is lowered.