Objective Droplet coalescence is a crucial step in the demulsification and dehydration of emulsions under pulsed electric fields. Due to the unclear mechanisms and influencing factors of droplet coalescence in pulsed electric fields this study aims to provide guidance and direction for future research. Method By comprehensively comparing and analyzing the relevant content of demulsification and dehydration of emulsions under pulsed electric fields this study summarizes the mechanisms of droplet coalescence and the factors affecting it. Results The main mechanisms of droplet coalescence in pulsed electric fields are dipole coalescence electrophoretic coalescence and dielectrophoretic coalescence. The primary factors affecting droplet coalescence are electric field strength electric field frequency and duty cycle all of which have optimal values to achieve the best coalescence effect. For emulsions with different physical properties pre-treatment of the emulsion can be performed during electro-demulsification to obtain better coalescence results. The influence of operating parameters and the formation of secondary droplets on the coalescence effect cannot be ignored. Conclusion Numerical simulation molecular dynamics and other technical means should be used to conduct in-depth studies on the droplet coalescence process and explore the universal mechanisms of droplet coalescence in pulsed electric fields. Meanwhile emerging technologies should be employed to conduct in-depth and systematic exploration and expansion of the formation of secondary droplets based on the coalescence mechanisms.