China's state-owned enterprises(SOEs) are facing an embedded integration of new functional mission,new classification reform and new digital development. These new tasks require SOEs to embrace digital strategic transformation and innovation for high-quality fulfillment of their national mission. Studying their digital transformation practices, this paper systematically explores the mechanism and path of embedding national mission into SOE digital transformation, and the mode selection of SOE digital transformation under different mission guidance. The findings are: (1) The SOE functional mission focusing on economic development,strategic support and public services in the new era is undertaken by for-profit, strategic and public functional SOEs; (2) the foreign circulation path based on the positioning mechanism-mapping mechanism and the internal consumption connection path for the state capital strategic positioning constitute a double two-way mechanism of embedding the national mission to the SOE digital strategic transformation, leading SOEs to build market-oriented, capacity-oriented and public-oriented digital transformation modes; (3) the three types of reform modes have respectively produced the action mechanism featuring agile strengthening,toughness strengthening and adaptability strengthening, which support the SOE classification performance. This paper attempts to make up for the research gap such as the lack of integration of the SOE digital strategic transformation mode by constructing the theoretical mode of SOE digital strategic transformation under the guidance of national mission, and reveals the intermediary mechanism of digital strategic transformation to support SOEs for fulfilling their functional missions.