MicroRNA (miRNA) links closely to the occurrence and development of many diseases, and the relationships between miRNA and mycotoxin and pathogenic bacteria also draw attentions. Therefore, in addition to clinical diagnosis, there is significant potential by sensing miRNAs for toxicity evaluation of food hazards. However, ultra-low levels, small inherent size and highly similar segments of miRNAs present a challenge to the profiling of miRNA expression, making effective methods crucially important. In this review, limitations of traditional miRNA detection methods are discussed. Then, a summary on miRNA sensing and imaging based on DNA nanostructure is provided. Next, signal amplification and ratiometric detection using sensitive electrochemical and fluorescence signals is focused. At last, challenges and potential opportunities of miRNA detection for wide application are proposed.