In order to construct a gene regulatory network model, a method combining correlation analysis and principal component analysis is proposed. Use Pearson's correlation coefficient for correlation analysis to construct an initial gene regulatory network. Then use the principal component analysis method to establish the trimming principle, so as to obtain a new gene regulatory network.  Using the expression data of 10 genes of Escherichia coli (Ecoli1) in Dream3 for testing, the results show that referring to the benchmark network under the gold standard, the gene regulation network obtained by the proposed method has high accuracy.