In order to achieve high spatial resolution and narrow spectral bandwidth imaging of laser plasma in updated SG-Ⅱ laser facility, the relations of the imaging quality of spherically bent crystal with image distance, Bragg angle and backlit size were discussed. First, spherically bent crystal imaging at diverse image distances, Bragg angles and backlit sizes were studied with a ray tracing program X-LAB. Then, a test experiment was carried out by using X-ray tube device. The results show that better two-dimension image could be obtained at the image distance of equal resolution of two dimensions, and larger the Bragg angle is, better the imaging is. Furthermore, smaller size of backlit is also helpful to improve the imaging quality. The experiment result agrees well with the expectation, a spatial resolution better than 14 μm in the image of the mesh. The results obtained contribute to the optimization design of the spherically bent crystal imaging system and precision diagnosis of laser plasma.