Abstract Prior research has primarily focused on electronic Word of Mouth (e‐WOM) in consumer markets, lacking in‐depth exploration of its dynamics within B2B contexts. Addressing this gap, our study investigates e‐WOM in B2B markets on industrial internet platforms. Specifically, we examine how digital platform capabilities can be leveraged to create positive e‐WOM through multi‐actor value co‐creation processes. Utilizing a case study approach, we analyze heterogeneous data from multiple sources to understand how digital platform capabilities—such as digital ecological capability, digital coordination capability, and digital innovation capability—promote multi‐actor value co‐creation (including intrapreneurship within the focal firm, support for complementary products or services, and users' reciprocal participation), thereby disseminating positive e‐WOM in B2B markets. Our findings provide insights into e‐WOM in B2B markets and reveal the mechanisms of multi‐actor value co‐creation through which digital platform capabilities activate e‐WOM. This study enriches the theoretical framework of e‐WOM in B2B contexts and underscores the significance of digital transformation in enhancing interaction and collaboration among multiple actors on industrial internet platforms.