Abstract: The Scientific Experimental system in Near SpacE (SENSE) consists of different types of instruments that will be installed on a balloon-based platform to characterize near-space environmental parameters. As one of the main scientific payloads, the middle and near ultraviolet spectrograph (MN-UVS) will provide full spectra coverage from middle ultraviolet (MUV, 200−300 nm) to near ultraviolet (NUV, 300−400 nm) with a spectral resolution of 2 nm. Its primary mission is to acquire data regarding the UV radiation background of the upper atmosphere. The MN-UVS is made up of six primary components: a fore-optical module, an imaging grating module, a UV intensified focal plane module, a titanium alloy frame, a spectrometer control module, and a data processing module. This paper presents in detail the engineering design of each functional unit of the MN-UVS, as well as the instrument’s radiometric calibration, wavelength calibration, impact test, and low-pressure discharge test. Furthermore, we are able to report ground test and flight test results of high quality, showing that the MN-UVS has a promising future in upcoming near-space applications.