Time-resolved diagnosis of the transient process using X-ray frame cameras (XRCs) is an important means in inertial confinement fusion (ICF) experiments. The sensitivity of the photocathode is a key parameter of the entire camera system. This letter aims to raise the quantum efficiency (QE) of the photocathode. With the changes in the deposition parameters, such as deposit angle, thickness of the coating in the channel, and vacuum of evaporation, the QE results are different. After testing and theoretical calculation, we find that there is a best matching value among these parameters. When the coating parameter meet this best value, the gain of the XRC can be improved significantly.