Recent work on alliance partner selection focuses on the relationship between partner features and alliance performance, while ignoring the influence mechanism of alliance partner features on different innovation types of firms. In this paper, based on proximity perspective, the influence mechanism model of alliance partner features on firms' dual innovation is constructed. Analyzing questionnaires and patent data of high-tech firms, it is found that (1) Technological proximity (TP) has a positive impact on focal firms' exploratory innovation (EXR) and exploitative innovation (EXI); (2) Knowledge coupling (KC) mediates the relationship between TP and dual innovation; (3) Social proximity (SP) positively moderates the relationship between TP and dual innovation, and positively moderates the relationship between TP and KC; Meanwhile, (4) there is a moderating effect of different levels of SP on the magnitude of the mediating effect of KC. By constructing a theoretical framework based on "proximity --knowledge coupling --dual innovation", this paper is helpful to draw scholars' attention to the relationship between proximity and dual innovation, and provide theoretical reference for firms to select alliance partners reasonably and efficiently.