The word positions for any given word in the whole collection are arranged in clusters. If we can use the method that can take advantage of clustering, excellent results can be achieved in compression of inverted file. However, the mechanisms of decoding in all the well-known compression methods that can exploit clustering are more complex, which reduce the ability of searching performance in information retrieval system (IRS) at some degree. In this paper, we proposed a new method that can facilitate coding and decoding of interpolative code by using the simply applied and high-speed models such as γ code and Golomb code in d-gap technique. This new method can exploit clustering well, and the experimental results confirm that our method can provide fast decoding speed and excellent compression efficiency.