水下应急封井装置是用于临时封堵井喷失控井口、重新建立井口防喷系统、防止井喷继续发生的应急装置。本文概述水下应急封井装置的封盖与封盖+分流的两类功能类型，以及独立于水下防喷器组的控制方式；介绍使用钻井船钻杆或工程船钢丝的安装方式，三类工具包对事故井进行处理与干预，以及根据事故井现场评估的实际情况进行安装位置的选择，并综述水下应急封井装置的全球资源及其主要的技术参数。

 The subsea capping stacks is an emergency device used to temporarily contain subsea blowout well, reestablish blowout prevention system. This paper outlines subsea capping stacks' functional types of cap, cap and flow, and separated control method independent from the control of subsea bop stacks; introduces its deployment mode via drill pipe from a rig or wire from a vessel, three kinds subsea incident response toolkit and the order preference for attachment points; and summarizes the global resources and main technical parameters of subsea capping stacks.