CRISPR/Cas-based gene editing system is one of the newly-developed and promising biotechnologies. It shows broad application prospects for gene editing, DNA and RNA imaging, regulation of gene transcription, gene detection and disease diagnosis, establishing animal disease models, and improving crop, etc. In this review, we overviewed the background and development history of CRISPR / Cas systems, discussed recently-investigated delivery methods including various nanocarriers, summarize the preclinical and clinical advances of CRISPR/Cas-based therapeutics, and introduced other application areas besides gene editing. Finally, we made an outlook on the challenges we need pay attention to, and the future application prospects of CRISPR/Cas technologies.