Abstract: The mechanical behaviors of dust particle in ESP(electrostatic precipitator)directly affect effect of tapping and removing.To improve the dust collecting efficiency of ESP, this paper makes use of the theory of corona and solid contact to study mechanical behaviors of dust particle in the electric field and on the collecting plate.The study result indicates that the Coulomb force, Van Der Waals force, Ross-linking force, electro-statically induced force and electric field force have obviously effect on mechanical behaviors of dust particle, and that the electric resistance has the very important function.