The invention provides a node voltage stability evaluation system and method based on a local measuring vector, and belongs to the technical field of voltage stability evaluation. Measuring is conducted on synchronous vector data of local nodes of a system, the system is simplified into an equivalent two-node system containing a target node according to a thevenin theorem, a new voltage stability criterion is proposed, no hypothesis is conducted on the load characteristic in the whole process, and a voltage unstability signal is given out when the target node load is excessively large; due to the fact that only the data of partial nodes of the power system are acquired, the computing amount is reduced; due to the fact that no hypothesis is conducted on the load characteristic, the theoretical universality and accuracy are guaranteed; the computing speed and stability evaluation accuracy are considered at the same time, possibility for real-time online evaluation of system node voltage stability is provided, a timely stability control measure is taken according to a real-time judgment result, and great help is provided for improving the safe and stable operation ability of the system.