Marxism-Leninism has become a widespread ideological foundation that is consistently and firmly pursued by the Communist Party of Vietnam (CPV) in its leadership orientation for national development. This research aims to explore and identify the distinctive issues in Friedrich Engels’ theoretical thinking regarding the formation of theoretical thinking based on practical experience, the close relationship between theoretical and scientific thinking, materialist dialectical thinking and mastering the scientific principles of philosophy. These orientations have become methodological guides for the CPV to apply to its leadership activities. This research was conducted based on the analysis and synthesis of available sources, with the main sources being the Marx-Engels Collected Works and some classical works written independently by Friedrich Engels, along with a synthesis of related studies. The results indicate that Friedrich Engels’ theoretical thinking has been studied, supplemented, developed, and creatively applied by the Communist Party of Vietnam in the renovation process in Vietnam, especially since the CPV initiated the renovation policy in December 1986. To date, Vietnamese socialist theory continues to be supplemented by Friedrich Engels’ theoretical thinking, which in his time had not been able to be experimented, contributing significantly to the development of the CPV’s theoretical understanding of political, economic, cultural, and social leadership, becoming an important guiding tool for the CPV to firmly lead the implementation of the renovation policy. Friedrich Engels’ theoretical thinking also holds important value in the struggle against erroneous, eclectic, dogmatic, and mechanical views on human perception and practical action.