At present,it is how to decrease the DNA volume that plays an important role in the development of DNA computing.In this paper,for the objective to reduce the DNA volume of 3-Dimensional Matching Problem which is a famous NP-complete problem,an improved DNA computing model based on the operations in Adleman-Lipton′s model and the solution space of the sticker-based model is put forward.Then,the divide and comquer is introduced into the DNA computing and a new DNA computing′s algorithm is proposed.In a computer simulation,the DNA strands of maximum number required was O(1.414n),the time complexity was O(15×n+30×q),the test tube complesity was O(1) and the longest DNA strand was O(15n/2+45q).Hence,the scale of 3-Dimensional Matching Problem may be enlarged from 67 to 134.This new algorithm is highly space-efficient and error-tolerant compared to the conventional brute-force searching,and can be scaled-up to solve large and hard 3-Dimensional Matching Problem.By the approach,we can also show DNA computing′s vast potentials for resolving NP problems.