A high-order tunable Bragg waveguide grating can be prepared on lithium niobate by using the methods of photolithography and titanium diffusion. Its related characteristics are analyzed. The effects of duty cycle, grating order, waveguide width difference and applied voltage on the reflective spectral properties of higher-order Bragg waveguide gratings are analyzed. The results show that the refractive index modulation depth, the maximum reflectivity and the zero bandwidth of gratings change periodically with the duty cycle, and the central wavelength shifts to the longer wavelength with the increase of duty cycle. When the best duty cycle is chosen for each order grating, the refractive index modulation depth is the largest, and the maximum reflectivity increases and the zero bandwidth decreases with the increase of grating length. With the increase of waveguide width difference, both of the maximum reflectivity and the zero bandwidth increase, and the central wavelength shifts to the longer wavelength. Moreover, with the increase of applied voltage, the reflective spectral shapes almost remain the same and the central wavelength shifts to the longer wavelength and presents a linear growth trend.