Abstract: Based on the various premises of national economics in Economic and Philosophic Manuscripts of 1844, Marx proceeded to investigate private property, opened the road of secular criticism of alienated labor theory and in the in-depth study of political economy, the construction of alienation labor theory began to be externalized from the subject phase transition to the phase of labor alienation. On the one hand, the practical dimension of Marx’s alienated labor theory implies that under the influence of Feuerbach and surpassing the latter, Marx realized the critique of Hegel’s objectivity thought; on the other hand, it implies that Marx has experienced from the early period of religious criticism to legal philosophy criticism and then to political economy criticism. In this way, the practical dimension of alienated labor theory has reached a high degree of historical reality in the process from subject externalization to labor alienation.