The present research, focusing on the politics of the second Pahlavi party line from 1336 to 1357, seeks to answer the question: why and how did Mohammad Reza Pahlavi followed party line as a democratic tool for advancing his political goals and what results did he achieve in this regard? The findings of the research, which were collected in a descriptive-analytical way (method), indicate that the second Pahlavi with party politics, on the one hand, followed the training of obedient cadres and the development of party supervision over the pillars of people's lives, and finally the development of totalitarianism. And, on the other hand, with the forced participation of the masses in the political scene as well as the democratic show, it has sought to guarantee the legitimacy of the government. But the results of this policy not only did not strengthen the Pahlavi government, but accelerated its collapse.