The purpose of this article was to examine the approach of Iran's international documents and criminal laws in proving evidence in the crime of money laundering. Among the most important crimes related to the financial and economic security of the country, which also has international dimensions and funds, is money laundering and the process of making illegal incomes from criminal activities inside and outside the country look legitimate. Considering that the crime of money laundering has spread today by relying on new tools and methods, it is important and necessary that the burden of proof and methods of proving this crime rely on the evidence of criminal proof contained in domestic laws on the one hand and international documents on the other hand. should be studied in order to evaluate both the proofs of this crime and the challenges that exist in citing these proofs to prove money laundering. The main question of the research is that, in relation to the proof of evidence in the crime of money laundering, how can the approach of Iran's international documents and criminal laws be explained? The main hypothesis of the article is that, in the international documents and criminal laws of Iran, attention has been paid to the way of proving the crime of money laundering. The results of the research show that, both in domestic laws and in international documents and regulations, attention has been paid to the method of proof, evidence of proof and the burden of proof, and the course of legislative developments in this regard according to the amendments approved in 2017 in the money laundering law (especially The notes of Article 2) which have been established in accordance with international documents and regulations, indicate that money laundering can be proven by relying on traditional evidence such as confession and testimony on the one hand and modern evidence such as electronic evidence collection.