Populism is one of the approaches that affects criminal policy in different stages of preliminary investigation, trial and sentencing and execution of the sentence. Considering the important role of populism in criminal politics and at the same time the important place of proceedings in the realization of judicial justice, the purpose of this article is to investigate populism in criminal politics in the stage of proceedings and the ways to limit it. The upcoming article is descriptive and analytical, and the library method has been used to investigate the mentioned topic. The results indicate that populism in Iran's criminal policy has become more prominent in several areas of economic crimes, violent crimes, crimes against public modesty, and crimes against drugs. In some cases, the attitude of the criminal justice system towards the suspects, accused and convicted of these crimes is based on popular policies and away from the principles and standards governing criminal law, in such a way that it considers the accused and criminals as the only cause of committing the crime. In Iran's criminal law, populism in criminal politics during the trial stage has accelerated the trial in a hasty manner, which causes the disregard of principles such as the principle of equality of arms and fair trial in general. Creating transparency in the proceedings and the need to adopt a minimal approach is the most important solution to limit populism in criminal politics at the stage of proceedings.