The invention provides a method and a device for identifying application. The method and the device are applied to network safety equipment. The method includes receiving application requests transmitted by the terminal equipment to an application server; judging whether first application table items with server characteristics identical to server characteristics of the application server are available in first application tables or not; determining whether the first application table items are usable or not when the first application table items with the server characteristics identical to the server characteristics of the application server are available in the first application tables; identifying the application according to application identifiers in the first application table items when the first application table items are usable. The server characteristics of the application server are carried in the application requests. Table items in the first application tables are the first application table items, and corresponding relations between the server characteristics and the application identifiers are stored in the first application table items. The application corresponds to the application requests. The method and the device have the advantage that the application identifying efficiency can be effectively improved.