Abstract: Elaborated the basic concept and parameter types of electrical energy quality.Discussed the characters and basic definition of voltage dip and its impact on chemical production.Analyzed the causes of voltage dip from both power system running and customer usage.Advanced some countermeasures from the aspect of construction of power network and voltage compensation of chemical enterprises to avoid voltage dip.Simply classified existing technical response level of voltage dip and voltage compensation devices to solve the voltage dip problem，and advanced some shortages of existing voltage compensation devices.