Abstract: Under the given temperature, pressure and water cut conditions, gas hydrate will develop during the production of gas well, which is a well recognized operational hazard. It could lead to serious accidents such as plugging of the choke, the gas production halt and the shut down of pipelines. In order to avoid the mischief caused by gas hydrate, combining graphic with statistical thermodynamics gas hydrates prediction models; using both VDW and RK cubic EOS to solve model of temperature drop when gas flowing through chokes. The steps of designing downhole throttling parameters are detailed introduced. Combining gas well data in-site, four different groups of gas hydrates prediction models and throttling temperature drop models are calculated and the results were compared with the actual field data. Results show that the research can supply a more reliable support for the technical design of gas hydrate prevention.