This study investigates how minimum wage affects small firms through spillover effects from large firms. Using firm-level panel data from Anhui Province in China, we find that after a minimum wage increase, small firms will reduce workers' wages and create jobs due to the inflow of displaced workers from large firms. This spillover effect is larger for micro firms and private firms, where minimum wage compliance tends to be lower. We also find that high-tech small firms are more affected than low-tech ones because of their greater demand for skilled labor. Our findings not only highlight the unintended consequences of minimum wage on small firms in China, but also help to explain the ambiguous employment effects of minimum wage on the covered sector in developing countries.