The wavelength selective switch (WSS) is now considered to be the most important wavelength engine technology,and will be the key component of next-generation optical networks for carriers all over the world. A novel WSS is theoretically and experimentally presented in this paper,which implements an one dimensional MEMS mirror to realize the function of wavelength switching,while the Hitless switching is achieved by a MEMS attenuator. Compared with traditional WSS implementing two dimensional MEMS mirror to achieve the two functions simultaneously,this novel WSS is manufactured based on mature technologies,so it is cost-effective and productive. The maximum attenuation of 34 dB,insertion loss of 6.4 dB,dispersion range of -1.64-6 ps/nm are reported,indicating a high uniformity with the simulation results.