Exon trapping and targeted regions trapping are commonly used in the second generation sequencing method. However, the needs of thousands of primers have made the process of work difficult. At the same time, the cost of synthesizing such amount primers using the traditional method is very high. In addition to trapping, gene expression library also require a lot of primers. But the traditional synthesized primers are not only cause difficulties to subsequent screening, but also reduce the probability of success, as well as bring the increased redundancy of gene library.