The invention relates to a digital network interactive teaching system, which comprises a computer, an input device and an output device, wherein time-division multiple address and asynchronous serial transmission modes are used between the computer, the input device and the output device, wherein the computer is orderly connected with a network communication card, a network communication switch and a plurality of interactive teaching terminals which are parallelly connected with the network communication switch through an ethernet line. A handwritten interactive teaching method in the digital network interactive teaching system is that a system starts a teaching program, a teacher selects a teaching mode, then a network connecting is built, and the system awaits students to login and enter a teacher end to do the handwritten interactive work with a student end. The system produces and stores interactive work data according to the selected teaching mode, and a teacher replays the interactive work data which is produced by the system to all students and evaluates the work. The network line uses an ethernet network to conveniently wiring in a whole network, the system combines a programmable gate array in field and a single chip microcomputer to control, which leads the steady and the reliability thereof to be higher compared with a multimedia computer network, the power dissipation is low, and the digital network interactive teaching system is economical and environmental.