A toroidally bent crystal X-ray imaging system was designed in order to detect the X-ray spectrum and diagnose the image of target on fusion device. The Johann point-focusing geometry aberration was calculated in theory. Ray-tracing simulations of an optical X-ray system based on the bent crystal working operating in Bragg conguration for monochromatic projection imaging of grid samples are presented, and the relation between the Bragg angle and the spatial resolution of the imaging system is investigated. The X-ray radiation from a small source is dispersed by a transmission grid placed in front of the toroidal crystal imager. Our successful applications suggest that the bent crystals may be used to image with high spatial resolution. This configuration retains the advantages of the bent mica crystal spectrograph while enabling the analysis of the spectral radiation. Spectrally and spatially resolved Kα spectra of Cu were observed.