Abstract. Monte Carlo method is also known as random simulation method. The more the number of experiments, the more accurate the results obtained. Therefore, a large number of random simulation is required in order to obtain a higher degree of accuracy, but the traditional stand-alone algorithm has been difficult to meet the needs of a large number of simulation. Hadoop platform is a distributed computing platform built on a large data background and an open source software under Apache. It is easier to write and run applications for processing massive amounts of data as an open source software platform. Therefore, this paper takes π value calculation as an example to realize the Monte Carlo algorithm based on Hadoop platform, and get the exact π value with the advantage of Hadoop platform in distributed processing.