本文针对供热空调系统偏大设计的现状，分析了设计过程中涉及的许多因素的不确定性本质；提出供热空调系统保证率设计的概念，它直接以室内热环境的保证率为依据去做设计，真正体现了工程设计中投资与功能的对立统一；给出随机分析方法的思路和开发智能集成化的建筑热环境分析系统的构想，为实现供热空调系统保证率设计打下基础。 This paper focuses on the status quo of the overlarge design of heating and air-conditioning systems, analyzes the uncertainty nature of many factors involved in the design process, and proposes the concept of the design of guarantee rate for heating and air-conditioning systems, which directly depends on the assurance rate of the indoor thermal environment. Doing the design truly reflects the unity of the opposites of investment and function in engineering design. The idea of ​​a stochastic analysis method and the idea of ​​developing an intelligent and integrated building thermal environment analysis system provide the basis for achieving the design of the guaranteed rate of heating and air conditioning systems.