The wavelength drift and performance decay of hyper-spectral imager are the main problems that must be solved for long-term operation in orbit. The Fraunhofer absorption line, which is unique in the solar radiation spectrum and the atmospheric backscattering radiation spectrum, can be used as the benchmark for the wavelength calibration. According to the requirement for wavelength calibration precision of instrument, the high precision solar reference spectrum was optimized, then 87 Fraunhofer absorption lines were selected by the convolution of instrument slit function. The system error caused by the line asymmetric and the random error caused by the instrument detection capabilities were analyzed. Based on maximum deviation and RMS, the exact positions for available 76 solar Fraunhofer lines were determined under the condition that the calibration accuracy was better than 0.01 nm. This study lays the foundation for high precision wavelength calibration of hyper-spectral imaging on- orbit.