The regulation boundary of adjustable load is one of the key data that needs to be mastered in advance for the safe operation of the power grid. For process-oriented processing industry（PI）, the accurate evaluation of its whole-process load regulation capacity is limited by multiple energy requirements and process coupling, as well as the process requirements and production tasks that must be met. To this end, a method to evaluate the whole-process load regulation capacity of PI considering the refined modeling of processes is proposed,which provides a boundary reference for the power grid to formulate the regulation plan. Firstly, the production process of typical PI is analyzed, and an equivalent model of generalized PI considering process classification is established based on the adjustment characteristics of processes, and a refined modeling method considering process classification is proposed. Secondly, considering the production constraints such as process coupling, multi-energy utilization, and production planning, the model to evaluate the whole-process load regulation capacity of PI is established. Finally, the effectiveness of the proposed method is verified by taking the cement industry as an example,and the effect of process regulation on the whole-process load regulation capacity of PI is explored.