Objective  To investigate the agreement and correlation between preoperative simulated vaults （SV） measured by 50 MHz full-scale ultrasound biomicroscope and postoperative real vaults in phakic posterior chamber implantable collamer lens （PPC-ICL） implantation. Methods  In this self-control study， 21 high myopia patients （37 eyes） undergoing PPC-ICL implantation were included at the Eye and ENT Hospital of Fudan University from May to July in 2014. The mean age was 30.0±9.0 years and the mean spherical equivalent was -15.60±5.74 D. Based on the preoperative examination， the correct diopters and sizes of the PPC-ICL can be determined. Then the simulated postoperative images， simulated lens， positions and SV were achieved using a Compact Touch STS UBM. One month after implantation， the real vaults were measured by UBM and Pentacam， which were recorded as VUBM and VPentacam， respectively. The correlation and agreement for the three vaults were analyzed with Pearson correlation analysis and Bland-Altman， respectively. Results  SV， differed significantly from VUBM and VPentacam （t=6.660， 9.658， P<0.01）. Correlation analysis showed that there were moderate correlations between SV and VUBM， SV and VPentacam （r=0.508， 0.557， P＜0.01）. For the postoperative vaults， the agreement between the vaults measured by the Compact Touch STS UBM and those measured by Pentacam was strongest [95% Limit of Agreements （LoA）=-0.07-0.22 mm]. In contrast， the 95% LoA showed clinically significant differences between SV and VUBM and between SV and VPentacam （95% LoA=-0.19-0.66 mm， -0.07-0.70 mm）. Conclusion  Compact Touch STS UBM can replace Pentacam clinically in postoperative vault measurements. There is still a certain gap between the SV measured by the Compact Touch STS UBM and the actual postoperative vaults.