Why did Marxism, as a revolutionary theory based on political realities of advanced industrial societies, successfully directed the political struggles in the name of the communist revolution in 20th-century Russia and China? Specifically, how the peasantry as a social class, portrayed as a negative factor in the communist revolution by Marx, gradually evolved into the alliance with the proletariat from Lenin’s description and the natural revolutionary power from Mao’s description? This thesis using the latest computer-assisted text sentiment classification analysis based on deep learning neural network, examines the peasantization processes of communist revolutionary theories from Marxism to Maoism. From the perspective of the peasantry’s role in the revolution, the study analyzes the processes that Lenin as the leader of the Bolshevik and Mao as the leader of the Chinese Communist Party, inheriting、reforming and developing Orthodox Marxism in order to meet their own revolutionary needs. Meanwhile, the study compares the processes of localization of Marxism and the coevolutionary processes between the revolutionary theories and the political realities occurring in the two countries during the communist revolutions. The study finds that during different revolutionary stages or confronted with different political realities, Lenin was inclined to opportunistically use the role of the peasantry, while Mao relatively strived to revise the peasantry’s revolutionary position as a whole social class in Marxist revolutionary theory and portrayed the peasantry as a tremendous revolutionary momentum in backward non-industrial countries. However, these two revolution theorists both emphasized the revolutionary role of the peasantry.