The cooking fume purifier in catering industry adopts dual functions of mechanical separation and electrostatic purification. The exhaust gas containing oil fume is sucked into the pipeline under the action of the fan and enters the primary purification, separation and balance device of the oil fume purifier. Gravity inertial purification technology is used to physically separate and balance large-size oil mist particles. The separated large oil droplets flow into the oil tank and are discharged under their own gravity. The remaining tiny oil mist particles enter the high-voltage electrostatic field, and the electrostatic working principle of two-stage separation of high and low voltage is adopted. The electric field of the first stage ionization plate charges tiny oil mist particles into charged particles, which are immediately adsorbed and partially carbonized after reaching the second stage adsorption electrode. At the same time, ozone excited by high-voltage static electricity effectively degrades harmful components, plays the role of disinfection and deodorization, and finally discharges clean air through the filter screen.