Abstract: One of NVST's scientific goals is to perform two-dimensional spectral scanning observations of solar active regions. Based on NVST's Multi-Band Spectrometer and High Dispersion Spectrometer, this paper proposes a switching and spectral scanning system of the vertical double spectrometer, which can realize the spectral scanning observation tasks of two mutually perpendicular spectrometers and participate in the realization of switching between the two spectrometers. The principle and process of spectral scanning observation is analyzed. Combined with the specific structure of the NVST's terminal instrument system, the optical-mechanical structure design and installation of the system are completed. And the performance test of the system is performed, including system stability, scanning straightness and scanning step accuracy test. The test results meet the expected functional requirements and accuracy requirements. The work can provide support for NVST to perform conventional spectral scanning observations.