The invention relates to a one-class sample-based voltage stability prediction judgment method. The method comprises the steps of obtaining a measurement value sample set of a stable running time period of a power grid; establishing a sample matrix of the measurement value sample set of the stable running time period of the power grid, compressing the dimension of the sample matrix, and updating the measurement value sample set of the stable running time period of the power grid; and obtaining a tested measurement value sample, judging whether the tested measurement value sample belongs to the measurement value sample set of the stable running time period of the power grid or not, and if yes, indicating that the power grid at a moment corresponding to the tested measurement value sample is stable. According to the method provided by the invention, classification and prediction can be performed only based on stable samples according to a characteristic of few instable samples of the power grid, and the problem that large-scale complex power systems cannot be really recovered because a power grid model is simplified in multiple aspects for research on power grid stability based on simulation software data is solved.