Due to the restrictions of energy & bandwidth on wireless sensor networks(WSN in short),how to utilize the limited resources to acquire available and reliable data from the sensor nodes becomes a hot topic.

Based on the domestic and international research results,the concept of the trusted database was proposed in this paper.

In this paper, the major works are as follows:In this paper, a method for text categorization based on the fusion of multiple classifiers was presented, reliability function was introduction to select the text that hard to give determine by the main classifier, for these texts, multiple classifiers were used to give the determine which category the unlabeled documents belong to by voting.

It was to evaluate the experimental result of single classifier using the reliability function,to classify the documents that were hard to be classified by voting.