摘要:在建设数字孪生城市与道路交通的背景下，本文通过分析数字孪生概念及其难点，探讨其背后的双向映射本质，推导出基于多元复合映射的数字孪生理论和体系。结合道路交通领域的专业特点和多元化的数据及引擎需求，提炼出“端边物云座擎”道路交通数字孪生体系，强调通过支持数据及引擎多元化适配的独立数字孪生底座中间层，构建“人车路环境”物理实体与全要素数字模型的双向映射和交互。案例验证表明，该体系可行且有效。

Abstract: In the context of constructing digital twin cities and road traffic systems, this paper analyzes the concept and challenges of digital twins, exploring the bidirectional mapping essence behind it. A digital twin theory and system based on multivariate composite mapping is derived. Considering the professional characteristics of road traffic and the diversified needs for data and engine integration, a road traffic digital twin system called "endpoint-edge-cloud-IoT-twinbase-engine" is proposed. This system emphasizes building bidirectional mapping and interaction between the physical entities of "human-vehicle-road-environment" and comprehensive digital models through an independent middle layer supporting data and engine adaptation. Case studies confirm that this system is feasible and effective.