Potassium (K) has an important effect on the growth and development of plants. Banana contains high K content than many other fruits, and its plant requires more K nutrient in soil. However, the soil in the banana-producing areas in China is generally de cient in K. Therefore, understanding the mechanism of banana K absorption may assis in providing effective strategy to solve this problem. This study used two banana varieties with contrasting K tolerance, 'Guijiao No. 1' (low-K tolerant), and 'Brazilian banana' (low-K sensitive)to investigate K absorption mechanisms in response to low K stress through miRNA and mRNA sequencing analysis. Under low K condition, 'Guijiao No.1' showed higher plant height, dry weight, tissue K content and ATPase activity. Transcription factor analysis results showed that it was mainly concentrated in MYB, AP2-EREBP, bHLH, etc. The sequencing results showed that 'Guijiao No. 1' had 776 differentially expressed genes (DEGs) and 27 differentially expressed miRNAs (DEMs), and 'Brazilian banana' had 71 DEGs and 14 DEMs. RT-qPCR results showed that all miRNAs and mRNAs showed similar expression patterns with RNA-Seq and transcriptome. miRNA regulatory network was constructed by integrated analysis of miRNA-mRNA data. miR160a was screened out as a key miRNA, and preliminary functional validation was performed. Arabidopsis overexpressed miRNA160a reduced tolerance to low K, and inhibited phenotypical traits such as root length, and reduced K accumulation. The overexpressed miR160a had a targeting relationship with ARF10 and ARF16 in Arabidopsis. These results indicate that miRNA160a may regulate K absorption in bananas through the auxin pathway. This study provides a theoretical basis for further research on the molecular mechanism underlying the response of banana plants to low-K stress and for molecular breeding.