Abstract：In view of the problem that the zenith tropospheric delay(ZTD) and precipitable water vapor(PWV) caused by the accumulated errors of the GPT2w model, we obtain actual data from seven radiosonde stations and two GNSS stations in Yangtze river delta region in 2017 to test the precision of parameters such as air pressure, temperature, water vapor pressure, weighted mean temperature (Tm) and ZTD of the GPT2w model, and combine the ZTD calculated by GNSS (GNSS-ZTD) and the Tm obtained from the GPT2w model to improve the PWV precision. The results show that the biases of air pressure, temperature and water vapor pressure near the ground are distributed at -3~4 mbar, -7~7 K and -9~2 mbar respectively, which is with high accuracy. The Tm obtained from GPT2w has good applicability in Yangtze river delta, with an annual average of -1.21 K bias and 6.89 K RMS. The mean bias and RMS of ZTD obtained from GPT2w model are 1.4 cm and 9.4 cm respectively, with precision that are significantly lower than that of GNSS-ZTD derived from actual meteorological data. The accuracy of PWV calculated by parameter fusion method is equivalent to GNSS-PWV. This method can be used to obtain PWV quickly when there is without actual meteorological parameters.