In order to study the interaction between turbulent intensity and flame propagation in closed space, 3D numerical simulation of ignition and flame propagation process in the equivalent ratio mixture of isooctane and air was carried out under the in-cylinder pressure of 1.1MPa and 1.4 MPa and different turbulent intensity by using a combustion chamber model established based on the experimental platform of rapid compression machine. The results show that the shape of flame becomes wrinkled and deformed due to the effect of turbulence fluctuation around the flame, which becomes more serious with the increase of turbulence intensity. The wrinkles and deformations of flame will intensify the turbulence fluctuation so that the interaction between flame and turbulence fluctuation strengthens, therefore influence the in-cylinder combustion.