提出了基于USIM（全球用户身份模块）卡的补丁下载机制，采用鉴权技术实现空中下载系统与动态链接库之间互相鉴权认证，保证两者间的相互信任；提出采用动态链接库技术实现补丁下载机制，并通过定义底层API来提供对补丁下载进行控制与管理，实现空中下载系统对USIM卡上的应用可以通过该机制下载修复或者升级的功能。

The mechanism of patch downloading based on USIM card is proposed in this paper. This mechanism adopts authentication technology to enable the co authentication between OTA (over the air) and dynamic linking library (DLL), ensuring the mutual trust. In the paper, DLL is also suggested to practise the patch download mechanism. In this approach the application on USIM card can be updated by OTA through the control and management of patch downloading provided by the definition of lower level API.