Drug resistance is a significant factor that hinders the success of cancer chemotherapy. The widely recognized mechanisms of drug resistance include changes to cell proliferation, cycle/apoptosis, drug metabolism/transport, DNA damage and the epithelial to mesenchymal transition. MicroRNAs (miRNAs), short non-coding RNAs with lengths of approximately 19-25 nucleotides, are related to cancer drug resistance, which is regulated by the aforementioned mechanisms. Based on the importance of miRNAs in regulating drug resistance, it is also necessary to take appropriate miRNA detection methods into consideration. To date, a number of advanced miRNA detection methods with high specificity and sensitivity have been developed, such as isothermal amplification-based methods, nanomaterial-based methods, chromatography-based methods, mass spectrometry-based methods and so on. Herein, biogenesis of miRNAs, the relationship between miRNAs and cancer drug resistance, and miRNA detection methods are introduced and discussed to facilitate the development of non-invasive diagnosis and inhibition of cancer drug resistance.