Based on the institutional theory, this paper constructs a model of institutional driving factors, political connection and firm’s participating intention in standard competition, which probes into the influencing mechanism of coercive, normative and mimetic factors on the participating intention in standard competition, as well as the mediating role of political connection. By using the structural equation model to analyze the data from 265 Chinese firms, the paper finds the coercive, normative and mimetic factors in institutional environment have significant positive impact on participating intention in the standard competition, and political connection plays a partial intermediary role in the influencing mechanism. This study systematically explores the non-efficient driving factors of standard competition. It not only enriches the theoretical research on the driving factors of standard competition but also helps firms to acquire legitimacy in the standard competition and obtain competitive advantages.