With the development of manufacturing, people benefit from using multiple mobile robots to complete tasks in various scenarios, and multi-robot planning coordination has become a hot research topic in recent decades. This paper introduces two popular multi-robot system applications: multi-robot exploration and multi-robot patrol. First, the two kinds of problems are introduced and compared. Then, typical methods to figure out the problems are presented, including the frontier-based and market-based methods for exploration and the v-Min algorithm and v-Neighbor algorithm for patrol. Finally, this paper gives the experiment results and conclusions of different methods.