In order to study the influence of the swirling jet of the gasification agent on coal gasification performance, the gasification process of Ningdong pulverized coal inside a GSP gasifier (2000 t/d) was simulated under hot conditions, and the results were compared with actual industrial parameters. A three-dimensional steady multi-phase turbulent flow model was established by ANSYS Fluent. The coupling effect of turbulent chemistry was considered by Species Transport model. The realizable k-E model was used for the gas phase flow. The P-1 model was implemented for radiation heat transfer. The heterogeneous reactions were irreversible surface reactions and the gas phase reactions were to reach equilibrium. The numerical results showed detailed information of flow field under direct jet and swirling jet. It indicated the swirling jet had a significant influence on coal gasification performance by analyzing the characteristics of flame, species, and gas-solid distribution. In other words, the swirling jet promotes the reaction efficiency between coal particles and gas phase, increases the residence time of pulverized coal, and temperature and species concentration distribution are more well-distributed. Furthermore, this work can better predict coal gasification behaviour under different conditions, so as to provide the theoretic support for subsequent sulphur removal and optimal design of the gasifier.