Homogenous distribution of individual phases in the composite electrode is critical to the overall electrode performance. In this work, we report a one-step synthesis method to fabricate Sr2Fe1.3Co0.2Mo0.5O6−δ-Gd0.1Ce0.9O2−δ (SFCM-GDC) composite electrode material for symmetrical solid oxide fuel cells (SSOFCs). X-ray diffraction analysis reveals that the characteristic peaks of the perovskite and fluorite phases are obtained in the SFCM-GDC powder via the one-step synthesis method without any observable impurities. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) indicate a better phase distribution of the composite electrode of SFCM-GDC via one-step synthesis than that via a mechanically mixing process. As a result, the area specific resistance (ASR) of SFCM-GDC electrode is effectively decreased to 0.036 Ω cm2 and 0.047 Ω cm2 at 850 oC in air and hydrogen, respectively, compared to that of 0.041 Ω cm2 and 0.074 Ω cm2 of the mechanically mixed SFCM and GDC (SFCM+GDC). The maximum power density of a cell with configuration of SFCM-GDC∥LSGM∥SFCM-GDC can reach 0.986 W cm−2, higher than that with mechanically mixed electrode of 0.894 W cm−2 at 800 °C. This work shows that one step synthesis method is an effective way to fabricate composite electrode with enhanced electrode performance.