This work addresses the integrated optimization of both the plant-wide material processing system and the utility system for a polyvinyl chloride (PVC) plant. In the plant-wide material processing system, vinyl chloride monomer (VCM) production process and VCM polymerization process are optimized to determine production allocation and switching operation of parallel equipment as well as raw material supply arrangement. In the utility system, power generation/supply plan is determined by combined heat and power (CHP) units and the state grid. The nonlinear electricity consuming characteristics of calcium carbide production process, CHP process, and electrolysis process are modeled based on the industrial data. A multiperiod mixed-integer nonlinear programming (MINLP) model of a PVC plant by calcium carbide method is proposed with the intent to enhance the profit and reduce the energy consumption. The proposed MINLP model is successfully applied to two cases originated from a real-world industrial plant in China and results provide valuable guidance for the company planning. The comparative results verify the effectiveness and superiority of the proposed plant-wide integrated scheme.