The ultraviolet (UV) image intensifier is the core device of an UV imaging system. Its imaging quality determines its ability to detect and image UV optical signals. The modulation transfer function (MTF) represents the system's ability to transfer information at different frequencies and is an objective indicator of image quality assessment. Based on the MTF test principle of slit imaging and the Fourier analysis method, a set of MTF test systems for UV image intensifiers is established in this study. MTF test experiments were performed on three UV image intensifiers. The MTF curve cutoff frequencies of the three UV image intensifiers were between 32 and 34 lp/mm, and the imaging quality of the three UV image intensifiers was compared based on the MTF curves. Finally, the standard deviations of the MTF values of several important frequency points obtained from repeated tests were lower than 0.02.