NV-diamond center is promising for various sensor application of magnetic field. This sensor operation requires two inputs of light source of 532 nm wavelength and micro wave, and red light is detected for the output. In most other case, inhomogeneous excitation by spatially holding the diamond against the light source of 532 nm, generally induces low SN ratio. In future, high efficiency and large-scale device will be required for large-scale homogeneous excitation. Therefore, we report a light circuit design of the proposal SiN waveguide for the integrated Diamond sensor to achieve a uniform excitation.