The　electric　field-driven　droplet　formation　technique　can　effectively　improve　the　formation　throughput　and　control　the　droplet　size,　which　is　important　for　the　application　of　microscale　droplets　in　biopharmaceuticals　and　chemical　analysis.　In　this　paper,　the　droplet　formation　characteristics　in　T-junction　microchannels　under　the　action　of　electric　field　are　investigated　by　coupling　a　three-dimensional　lattice　Boltzmann　method　(3　D　LBM)　with　the　leaky　dielectric　model,　focusing　on　the　effects　of　electric　capillary　number,　a　flow　ratio,　and　a　viscosity　ratio　on　the　droplet　size.　It　is　shown　that　as　the　electrical　capillary　number　increases,　the　non-uniformly　distributed　electric　force　stretches　the　dispersed　phase　to　form　a　Taylor　cone　and　increases　shear　force　at　the　interface　of　the　two　liquids　to　overcome　the　surface　tension　force.　This　facilitates　the　transition　from　squeezing　to　dropping　and　reduces　the　droplet　size.　At　high　flow　ratios,　increasing　the　electric　capillary　number　leads　to　a　pinning　effect　between　the　dispersed　phase　and　the　wall,　which　intensifies　the　compression　of　continuous　phase　on　the　neck　of　dispersed　phase,　resulting　in　a　significant　decrease　in　the　droplet　size.　As　the　viscosity　ratio　increases,　the　vortex　resistance　caused　by　electrical　force　decreases,　and　thus,　the　electric　field　effect　will　dominate　the　droplet　formation　process.　Published　under　an　exclusive　license　by　AIP　Publishing.