Against the dual background of implementing the fundamental task of fostering virtue through education and cultivating and developing new-quality productive forces, constructing an ideological and political education community for postgraduates has become an important direction for the reform of higher education. Focusing on colleges and universities in Heilongjiang Province, this paper combines the Marxist community thought and the concept of “whole-process, all-round, and all-staff education” to construct a “five-in-one” framework of the postgraduate ideological and political education community, which includes “value synergy, subject synergy, curriculum synergy, process synergy, and environment synergy.” By analyzing the practical difficulties faced by colleges and universities in Heilongjiang Province, such as the uneven distribution of ideological and political education resources for postgraduates and insufficient subject collaboration, this paper discusses the construction logic and implementation strategies of the postgraduate ideological and political education community in colleges and universities of Heilongjiang Province from three dimensions: theoretical foundation, practical expansion, and guarantee mechanism. It aims to provide references for promoting the high-quality development of postgraduate talent cultivation in the Northeast Old Industrial Base.