Abstract: The key and bottleneck of PPP-RTK application is the generation of atmospheric correction model with fast convergence and high reliability.The PPP-RTK atmospheric correction model generation method mentioned above was investigated.The fast convergence and reliability were ensured by iterative constraints and time domain constraints，and the horizontal 10cm（95%）positioning accuracy was achieved in 45s using Wuhan CORS.On this basis，Hong Kong CORS was used for further validation and analysis.Although increasing the grid density can improve the positioning accuracy，the amount of information is increased.It is necessary to consider the positioning effect and the amount of broadcasted information，and the latitude and longitude of grid size for general users are suggested to be set at 0.5°~0.8°.The spatial distribution of reference stations must be reasonable and uniform，and it was proposed that virtual reference stations can be added within a reasonable range to constrain the generation of atmospheric correction models，thus ensuring their convergence and reliability.

Key words: fast convergence, high reliability, PPP-RTK, atmospheric correction model, virtual reference station