We introduce a simple method of preparing high‐performance composite photo‐anode by in situ self‐assembly gold nanoparticle (Au NP) on Titanium dioxide (TiO2) electron transport layer for dye‐sensitized solar cells (DSSCs). By transmission electron microscope (TEM) test, the size of Au NP is about 5 nm. Energy disperse spectroscopy (EDS) shows that self‐assembly metal nanoparticles are evenly dispersed in the photo‐anode. Due to the localized surface plasmon resonance of Au NPs, the absorption of the composite photo‐anode in the visible light is enhanced. And the result of electrochemical impedance spectroscopy (EIS) showed that the impedance of electron transmission is reduced and the electron life of solar cell is increased. As a result, the overall power conversion efficiencies (PCEs) of Au/TiO2‐DSSCs significantly improved from 5.74 % to 7.05 % under optimal condition. What's more, the improvement in PCE does not affect its stability. We think that this work can improve the efficiency of solar cells by constructing Au/TiO2 composite photo‐anode, which is beneficial to its commercial application. [ABSTRACT FROM AUTHOR]