The invention provides an experimental system for voltage stability testing of an AC/DC parallel power network. The system comprises a real-time digital simulator, a digital-to-analogue conversion circuit, a signal power amplifier and an analogue-to-digital conversion circuit, wherein a digital simulated numerical variable signal in the real-time digital simulator is converted into an analogue variable signal through the digital-to-analogue conversion circuit and is output to the signal power amplifier, the signal is changed into an electric variable of the secondary side of an actual transformer through power amplification and is output to an actual power transmission and distribution device (an automatic control device or a protective device), and an output feedback input signal generated by the actual power transmission and distribution device under the action of the electric variable is input into the real-time digital simulator through the analogue-to-digital conversion circuit and then acts on a digital simulation model. In this way, connection between a digital model and a physical object is achieved, the digital-physical closed-loop simulation experimental system is formed, and then the problem that no effective detection mean is available for a power transmission and distribution device is solved and unification of the digital simulation model and an equipment test model is achieved.