In the paper, different methods for pile foundation underpinnings under complex conditions are discussed and the advantages and disadvantages of such pile foundation underpinning methods as grouting reinforcement method, anchor pile method, root pile method and "pile+beam" method are analyzed. On basis of the actual conditions of Wuyangcun arcade on Line 5 of Guangzhou Metro, the underpinning scheme of pile+beam structure installed in pilot tunnel is determined. Furthermore, the detailed execution process of the scheme and the points to which attention should be paid during design and construction of the scheme are presented in the paper.