The invention discloses a business and data quantity control-based priority scheduling method, and relates to the field of power system information technology applications. At present, an interface is customized and developed when an access demand of a business system is received each time, so that an interface technology is simplex and an interface quantity is large. The method comprises the steps of dividing a unified interface platform into a plurality of sub-tasks for performing a query after a request of an external business system is received, and defining a priority of each sub-task; and executing the sub-task with the highest priority in a special thread pool, executing the sub-tasks with the non highest priorities in a general pool, when an executive thread quantity of the special thread pool reaches a maximum value, executing the task with the highest priority in the general pool, if an executive thread quantity of the general thread pool also reaches the maximum value at the moment, executing the task with the highest priority in an emergency thread pool, and if the thread quantities of the three thread pools all reach the maximum executive quantity, enabling subsequent tasks to be in waiting states. According to the technical scheme, system congestion is avoided and it is ensured that key businesses are executed preferentially and low-priority businesses are stably finished.