The leadership of the Communist Party of China is the fundamental guarantee for further comprehensively deepening reform and promoting Chinese-style modernization. The modernization transformation of rural grassroots Party building is the key to the realization of Chinese modernization in rural areas. Based on the empirical research of the whole country, this study constructs a two-dimensional analysis perspective of politicized construction and organized action from the perspective of Party building function, divides rural grassroots Party building into four types including formalization Party building, suspension Party building, involution Party building and organized Party building, and analyzes the performance, distribution and causes of each type of Party building. The study holds that the organized Party building with strong political construction and strong organizational action ability is the direction of the modernization transformation of rural grassroots Party building. The political structure of “Party building guidance and three governances” provides political conditions for organized Party building. Organized Party building can redistribute grassroots public power, which not only ensures the political leadership of the Communist Party of China, but also endows grassroots society with political vitality. The demand for distributive mobilization action provides the era conditions for the organized Party building. Under the background of resources going to the countryside, the grassroots Party organizations need to form rules recognition aggregation and collective action consensus through the allocation of resources, so as to realize the “re-politicization” of farmers. The innovation of the theoretical discourse of “the mass line” provides ideological support for the transformation of rural grassroots Party building, and the mass route in the context of organized Party building has new theoretical connotation. To move towards organized Party building, it is necessary to take affairs as the clue and the mass line as the value to run through political organizations and organizational society, extend the resources to the countryside into governance ability in function, transform the overall requirements of central integration into local technical practice, and respect the adaptability and creativity of rural grassroots Party building.