设计安全策略模型时应考虑安全策略的时序特性和灰色特性，还应综合考虑保密性、完整性和可用性三方面的需求。已有的安全模型没有描述时序性和灰色特性，而且一般只侧重描述保密性或完整性。为此，本文提出了动态灰色时序系统（简称ＤＧＴＳ）。本文详细描述了ＤＧＴＳ，以及基于ＤＧＴＳ的动态语义设计的灰色时序安全策略规范语言ＧＴＳＬ。 The security policy model should be designed with the timing and gray features of the security policy in mind. The security, integrity, and availability requirements should also be considered together. Existing security models do not describe timing and gray features, and generally focus on describing confidentiality or integrity. To this end, this paper presents a dynamic gray timing system (referred to as DGTS). This paper describes in detail the DGTS, as well as the GTSL, a gray sequential security policy specification language based on DGTS dynamic semantic design.