Abstract: In view of the current source design technology used in hot cathode ionization vacuum gauge electrical parameter calibration device, a single OPAMP based power supply is proposed.And a non-idealized model is set up to analyze the power supply as mentioned.The correctness of the model is verified by PSPICE simulation, and a comprehensive simulation analysis of the circuit performance is performed.The relative change rate of the output current at 1 GΩ is 0.3 ppm and the device adapt to 100 MΩ~100 GΩ load.The device as mentioned solves the problem that the current source of the hot cathode ionization vacuum gauge electric parameter calibration device is not suitable for the ultra-high ionization vacuum gauge of low-position ion current sampling.It has the ability to calibrate different types of hot cathode ionization vacuum gauge ion current amplifiers and provides theoretical basis and reference for the development of ionization vacuum gauge electrical parameter calibration device.