CO2 capture using ammonia solvent is an alternative to the conventional amine-based CO2 capture technology. While ammonia escape is one of the main barrier limiting its implementation. The present work reviews the current status of ammonia escape mechanisms and its inhibition technologies. The chemistry of ammonia-based absorption and desorption are analyzed, and the mass transfer of the ammonia escape are presented and discussed. Most suppression approaches for ammonia slip are in lab- and bench-scale studies. The representative development of the pilot-scale tests involves NH3 abatement and recycling process and chilled ammonia process (CAP). Some other novel processes have been reported the potential to reduce ammonia slip significantly and relatively lower energy penalty, but some technical issues including the process modification and parameters optimization should be resolved to secure economic feasibility. Integration of different ammonia inhibition approaches is suggested for the future development of ammonia slip suppression process.