Transmission enhancement of nanohole array has very important applications and prospects in many fields. Numerical simulation on transmission enhancement of metallic nanohole array is performed with finitedifference time-domain (FDTD) method. The factors such as round hole radius, film thickness, array cycle, and different materials are analyzed, and changing trend of transmission enhancement spectrum is discussed under the conditions of different parameters. Studies show that large round hole radius and thin film are helpful to the improvement of transmission enhancement, and larger hole array cycle is not conducive to transmission enhancement. The effect of different shape of nanohole on transmission enhancement is discussed, and rectangular hole array is used for comparison. Finally by changing thin film material the corresponding transmission performance is calculated.