With the development of global economy, marine transportation has been presenting busier scene, global coastal port, especially the throughput of China port continues to increase, all kinds of dangerous chemicals transports and the increased wharfs, which is because the geography particularity of waters, also added the ship fire control work new difficulties. For the particularity of large oil tankers and various inflammable and explosive chemicals transport ship, this article briefly introduced the sea foam fire extinguishing system. Firstly, the selection of proportion mixer is introduced, and then briefly introduces the principle and characteristics of fixed deck foam fire extinguishing devices.