Aiming at the characteristic of coaxial Bragg structure, design a coaxial Bragg reflector corrugated with sinusoidal ripples operating at Ka-band. Introduce the coupled mode theory and the CST software, based on of this, research its parameter design and numerical simulation. Results show that good agreement between the multi-mode theory and the CST software; In fact, by changing the initial phase, sinusoidal ripple amplitude, shape of gradient and gradient angle and windowing-function technique can improve the capability of the frequency response. These characteristics of a coaxial Bragg structure are favorable to improvement of the performance as a reflector or a filter in its applications.