The ventilator was an important equipment for coal mine safety production, which applied widely in coal field. With the development of computer technology, it was possible to make numerical simulation of fan flow field. Pressure of fan blade was mainly considered in working process of ventilator. In order to understand the influence of ventilator inlet flow on pressure field distribution of fan blade, a certain type ventilator used in main channel of mine was taken as an example, commercial fluid analysis software CFX was selected to make fluid dynamics analysis. Therefore, distribution features of ventilator internal flow field were obtained, at the same time, a method of solving blade pressure distribution automatically was proposed as well, which analyzed its influence to blade pressure field by changing inlet flow parameter so that provided theoretical reference for optimization of blade.