The effects of salt stress on plant growth were mainly caused by ion toxicity, osmotic stress and secondary oxidative stress. The expression of the related gene activated rapidly and carried out transcriptional regulation, then the corresponding protein is synthesized to control metabolite synthesis and ion transport to regulate the osmotic balance when plants under salt stress. With the rapid development of modern molecular biology, the study of salt tolerance mechanism of plants under salt stress has also deepened to the level of transcriptome, proteome, metabolome and ionome. The “omics” research of plants under salt stress provided a powerful tool for salt tolerance gene identification and the mining of iconic metabolites. This paper mainly summarized the methods and the application of transcriptomics, proteomics, metabolomics and ionomics under salt stress. The mechanism of salt tolerance was revealed, which provided a support for the selection and cultivation of excellent salttolerance plants. It also has an important theoretical and practical value.