The article examines the peculiarities of understanding and implementing the principle of legality in the Soviet period. Using the example of studying the legal process in the sphere of application of law in relation to persons who do not fulfill constitutional obligations to engage in socially useful work, strict observance of the principle of legality in the period under consideration is substantiated. The dynamic development of law in modern reality should take into account the historical and legal experience of domestic law enforcement, which is what the theory of law and state focuses on.