In order to obtain a mechanism which is suitable for numerical simulation of combustion process in EAN thruster， a detailed combustion mechanism for EAN is presented based on the existing mechanism containing EAN evaporation products nitric acid and ethylamine，and a skeletal mechanism for EAN combustion consisting 82 species and 291 reactions is obtained by simplifying the detailed mechanism through an integrated reduction method that contains rate of production （ROP） analysis and sensitivity analysis. The ignition delay time， species profiles in premixed laminar flames and shock tubes for ethylamine reaction and species profiles in shock tubes for nitric acid reaction are simulated by using detailed mechanism and skeletal mechanism. Validations for two mechanisms are presented by comparing their simulation results and experimental datas. The validations show that simulation results of skeletal mechanism are in agreement with experimental datas and predictions of detailed mechanism， which proves that the skeletal mechanism is credible. The obtained skeletal mechanism provides a reaction mechanism model for numerical simulation of combustion process in EAN thruster.