The invention provides a resource control method of a demand side. The method comprises: monitoring an operation state of a power grid system, determining a security level, determining a control timescale corresponding to the security level, selecting a resource control mode of a demand side, issuing relevant control information and responding to the control information. Besides, the invention also provides a resource control system of a demand side. The system is composed of a communication module, a monitoring module, a data storage module, and a processing module that are connected in sequence through a network cable. According to the invention, the control demands of the system can be met and matched precisely; while the service real-time requirements in various scenes are met, diversified selection is realized and larger participation space is provided for the user; with control mode selection strategies corresponding to different time scales, characteristics of all control modesare localized accurately, so that the service needs of different time scales can be met well; and on the basis of load-user-integrator-grid multi-space-scale control, adaptability to service needs ofthe system under different granularity levels is improved.