This paper reports the experimental research of optical channel waveguides in Z-LiNbO3 crystals by femtosecond pulses. The laser scanning trajectory is controlled by the five power function program. A 1×4 optical splitter was prepared by the horizontal scanning when the pulse energy is 270 mW, the scanning speed from 50 μm to 200 μm per second. The result shows that the scanning speed is slower, and the repeat times are more, the waveguide width is wider.