Abstract:By collecting and packing up a series of numerical control (NC) machine tool truncated failure data, the data were assumed to be two parameter Weibull distribution and related parameters were obtained. At the same time, the relevant inspection and test of hypothesis were validated, and the mathematical model of batch of NC machine tool failure interval time distribution was concluded. Moreover the related index of reliability of NC machine tools are determine, as well as its observation values, point and region estimation, and etc., which provide reference for reliability research of the machine tool.