Efficient full-text searching is a big challenge in Peer-to-Peer (P2P) system. Recently, Distributed Hash Table (DHT) becomes one of the reliable communication schemes for P2P. Some research efforts perform keyword searching and result intersection on DHT substrate. Two or more search requests must be issued for multi-keyword query. This article proposes a Sliding Window improved Multi-keyword Searching method (SWMS) to index and search full-text for short queries on DHT. The main assumptions behind SWMS are: (1) query overhead to do standard inverted list intersection is prohibitive in a distributed P2P system; (2) most of the documents relevant to a multikeyword query have those keywords appearing near each other. The experimental results demonstrate that our method guarantees the search quality while reduce the cost of communication.