The carbon-supported fuel cell platinum catalysts 20%Pt/C were prepared by one-step microwave-colloidal method. The influence of different factors, such as the concentration of nitric acid used in carbon powder catalyst carrier, the microwave reaction time of preparation for the catalysts and the dosage of ethylene glycol reductant on the catalyst electric catalytic activity was compared here. It is found that the activity is the best when the concentration of nitric acid is 40% and the microwave reaction time is 70 second during both anode and cathode reaction. Interestingly, when the catalyst is used for methanol oxidation, lower dosage of EG leads to higher activity, while for oxygen reduction higher dosage of EG is better instead. X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) and cyclic voltammetry (CV) etc, revealed that the structure, crystal structure and the particle size did not change much by different preparation conditions whereas the electrochemical special surface area and electric catalytic activity have a significant influence.