The invention discloses a method for controlling network bandwidth and flow of an electrical power system. The method comprises steps as follows: 1, a user terminal is divided into a fixed reservation group, a dynamic reservation group and a common group by bandwidth control equipment; 2, data requiring network transmission are compressed and then transmitted; 3, the user terminal for sending data is identified, and a group which the user terminal for sending the data belongs to is judged; 4, a bandwidth with a fixed value is allocated to the fixed reservation group of the user terminal; 5, the maximum bandwidth is allocated to the dynamic reservation group of the user terminal during data transmission, and the minimum bandwidth is allocated if the maximum bandwidth is absent; and 6, the remained bandwidth is allocated to the common group of the user terminal after the fixed reservation group and the dynamitic reservation group are occupied. Through setting control of the flow control equipment, a core business can be guaranteed, internet behaviors of each user are effectively managed, the work efficiency of a teaching worker is improved, the bandwidth use efficiency of an outer net link of the network is improved, and the investment cost of export bandwidth is reduced.