Abstract:Pulsed plasma thruster(PPT) is regarded as an electric propulsion device for some propulsion mission of micro-spacecraft for its small thrust，light weight and low power. However, it has been criticized for its inefficiency. In view of this situation，adopting polytetrafluoroethylene (PTFE) as the propellant, PTFE is doped with 2, 5(6), 10 and 15 percent C or Cu to make two new types of propellant as the research object. The discharge voltage and current waveform were recorded, the ablation mass weighted under three different discharge energies（1J, 1.44J, 2.25J）, and the impulse bit, specific impulse，efficiency of PPT were estimated based on the results. The species, characteristics of plasma were also detected and diagnosed with the emissive optical spectrometer. The research results show that the ablation mass increases with the increase of the doping amount; the impulse bit increases with the increase of the C dopant, and the PTFE-Cu-10% impulse bit is the largest, which is 56.47(μN?s); PTFE-C-2% and PTFE-Cu-10% have the best performance in all C and Cu dopant PTFE specimens, and they promote the ionization process to some extent, thereby improving the thruster efficiency.