In order to give the test and debugging of the medium-voltage power line hardware circuit convenience in the laboratory, this paper designs a medium-voltage power line channel noise generator based on virtual instrument technology. LabVIEW is used to program most and noise data is generated in the computer. The virtual instrument capture card outputs noise signal. Experiments show that the noise generator mostly uses software programming.And it solves the long-time, high-cost problems of traditional instruments. And it can output noises which matches medium-voltage power line channel noise characteristics.So the design can give the test of hardware circuit’s modulation and coding convenience.