Transfer processes can be effectively enhanced by external fields,and the heat transfer process enhancedby electric field is a research hotspot in nowadays.In order to reveal the thermodynamic mechanism of convectiveheat transfer enhanced by electric field,fundamental thermodynamic equations including the influence of electricfield are put forward based on the energy postulate,enthalpy and Gibbs function are redefined with the effect ofelectric field,and the expressions of the partial derivatives of enthalpy and temperature with respect to electricfields are derived.The results indicate that,for most liquids in a valid temperature range,the enthalpy decreasesin isothermal process and the temperature increases in adiabatic process with the increase of external electric field.When an external electric field is applied on the heat release stage,the decreased enthalpy of the liquid mediummeans that more heat can be released,while the increased temperature of it means that the heat release to lowerreservoir tends to be more effective.Thus,it is concluded that the electric field effectively enhances the convectiveheat transfer.Based on the proposed thermodynamic mechanism,a principle diagram is finally presented to de-scribe the convective heat transfer enhanced by electric field.