Abstract: In order to obtain miRNAs expressed differently between oral cancer tissues and normal tissues, the role of miRNAs in tumor development was studied on the molecular level. Gene chips of oral cancer and normal tissues were screened and downloaded from the geo database. The differential expression of miRNAs between oral cancer and normal tissues was analyzed using GEO2R. The function annotation and KEGG signal path analysis of miRNAs are analyzed with the FunRich software. By analyzing the data of GSE124566 and GSE113956, 109 and 1 079 differential miRNAs were screened, including 41, 673 up-regulated genes and 68 and 406 down-regulated genes respectively. 30 miRNAs were screened. The 16 up-regulaed genes were involved in the biological process of intercellular communication, the cell components include nucleus and the molecular function mainly includes transcription factor activity. The 14 down-regulated genes were involved in the biological process of signal transduction, the cell components include cytoplasm, and the molecular function is transcription factor activity. Through the bioinformatic analysis of the oral cancer microarray data, it is found that 30 differentially expressed miRNAs are important miRNAs in the occurrence and development of oral cancer, including vesicle mediated transport and nucleotide metabolism. 13 796 target genes were predicted, and 10 target genes were screened with the PPI interaction analysis.