Abstract：We select the FES2004, NAO.99b, FES2014b, EOT20, GOT4.10c and TPXO9.5a ocean tide models for OTLD correction of 253 CMONOC GNSS stations, and analyze the influence of unmodeled or inaccurate OTLD on CMONOC GNSS coordinate time series and zenith troposphere delay(ZTD) estimation. The results show that the greater the influence of OTLD, the more obvious the improvement effect and difference of different tide model corrections on the wRMS of GNSS coordinate time series. The maximum improvement effect can be more than 52%, and the maximum difference can be up to 11%. The maximum amplitude of GNSS mixed signal caused by the difference of tide models is about 4 mm, and the corresponding periods are mainly 14.8 d and 365 d. There is a quasi-linear relationship between OTLD and ZTD deviation, and the better the practicability of tide model, the more obvious the linear relationship between them. FES2014b model has a better OTLD correction effect on the wRMS of GNSS coordinate time series, the mixed period, and the ZTD estimation.
