In order to improve the reproducibility in mirror metrology, a mirror mount used in high repeatability interferometer is developed, and simulations and testing are undertaken to evaluate the device. The deformation of the mirror due to disturbance in the mount is analyzed with ANSYS and the reproducibility of different metrology mount is calculated. The calculation results indicate that root mean square (RMS) of the reproducibility that the mount can be achieved is better than 30 pm. The structure of the device is finally confirmed, and reproducibility testing is carried out on high repeatability interferometer, the testing result indicates that RMS of the reproducibility caused by the mount devise is better than 70 pm, which meet the 0.1-nm RMS requirement of the error budget.