Abstract: In light of the prevalent dual pressures of compressed construction durations and cost overruns commonly encountered during the construction phase of expressways, an information-based management system driven by both construction period and cost is developed. This system has successfully addressed the technical challenges associated with the dynamic coupled management of construction period and cost. By integrating the theoretical frameworks of the Critical Chain Project Management (CCPM) and Earned Value Analysis (EVM), a dynamic coupling mathematical model is formulated. This model serves to quantify the non-linear superposition risks of construction period and cost. Additionally, a two-dimensional matrix model with dual-core driving mechanisms iis established. This model enables a refined classification of risk levels into four quadrants (red, orange, yellow, and blue), thereby facilitating the precise matching of management strategies. Based on a hierarchical architecture design, a five-tier system framework encompassing 'infrastructure, data, business, application, and security' is proposed. The integration of the LSTM-ARIMA hybrid algorithm within this framework enhances the prediction accuracy of construction period and cost. Moreover, blockchain technology is applied to solidify the rules of measurement and payment. Relying on a lightweight interactive interface (WeChat mini-program with dialect voice recognition accuracy of no less than 92%), the system significantly reduces the usage threshold. Empirical studies indicate that this system effectively transcends traditional management barriers and realizes the dynamic coordinated control of construction period and cost. As a result, The proposed method offers a quantifiable and scalable implementation pathway for the digital transformation of expressway construction.