A metal ion plasma thruster (MIPT) structure using a trumpet-shaped insulated anode with double micropores (TsIADM), which consists of a frustum-cone-shaped cathode, insulating sleeve, trumpet-shaped anode and anodic insulating layer with double micropores, is proposed. The differences in discharge characteristics and propulsion performance of the TsIADM-MIPT and two other structures, a trumpet-shaped semi-insulated anode MIPT and a conventional trumpet-shaped exposed anode (TsEA) MIPT, are compared and analyzed. Furthermore, the influence that the position of the double micropores has on the MIPT performance is discussed. The results show that the thrust and thrust-to-power ratio are all largest when the double micropores are set at the top end of the inner insulating layer of the trumpet-shaped anode (TsIADM(T)-MIPT). When compared with the TsEA-MIPT, the TsIADM(T)-MIPT demonstrates thrust and thrust-to-power ratios that are improved by 11.6 and 9.5 times respectively. The discharge parameters show that the number of charged particles flowing into the anode in a single shot decreases obviously when adopting the TsIADM(T). The discharge phenomena indicate that compared with the TsEA-MIPT, the luminescence intensity and ejection performance of the plasma plume using the TsIADM(T)-MIPT increases significantly. When the capacitor energy of the system is 5 J, Langmuir probe data show that the plasma density and plasma propagation speed are increased by 16.5 and 4.6 times respectively. These results are believed to be fundamental to the physical mechanisms behind the increased thrust and thruster-to-power ratio of the TsIADM(T)-MIPT.