Proton conducting oxide BaCe_0.7Zr_0.1Y_0.2O_3-d (BCZY7) was synthesized by high temperature solid-state reaction method, which crystal structure and microstructure morphology were characterized. The anode-supported button solid oxide fuel cell (SOFC), NiO-BCZY7/BCZY7/La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ(LSCF)-BCZY7, was fabricated by combining the dip-coating and co-sintering processes. It operated by using H₂ (containing 3vol% H₂O) as fuel and ambient air as oxidant. The maximum power density of the cell reaches 203, 123 and 92 mW×cm^-2 at 600, 550 and 500 ℃, respectively. However, traditional SOFCs based on (ZrO₂)_0.92(Y₂O₃)_0.08 electrolyte usually display only tens of milliwatts output per unit area at 600 ℃. Proton conducting electrolyte greatly improves the low and medium temperature performance of SOFCs and provides a promising solution to reduce SOFCs’ operating temperature.