Synthetic biology aims to establish a complete set of engineering principles, theories, and methods, via the rational design and assembly of basic biological parts, for the goal of effective implementation of complex biological systems with programmable functions. In recent years, with emerging novel classes of programmable genetic parts, in particular, the establishment and optimization of CRISPR and CRISPRi technology platforms, synthetic biology is entering a new era. This review summarizes recent advances on CRISPR genome editing and gene regulation technologies, their applications in constructing programmable biological parts, and their roles in building sophisticated gene circuits. We also provide a future vision on how synthetic biology can transform medicine (named medical synthetic biology, MSB) and therapeutics.