The Charge-exchange Recombination Spectroscopy (CXRS) is an advanced technique for measuring Tokamak plasma temperature and spatial distribution. In order to satisfy the research demands of CXRS system of China HL-2A Tokamak, such as wide spectral range (470~660 nm), wide view field (535.34 mm), wide light beam diameter (110 mm), good spatial resolution (14 channels) and matching with the numerical aperture (0.22) of follow-up optical fibers, an optimized optical signal acquisition system consisting of one mirror and four lenses is designed by using the optical design software ZEMAX, and the aberration is also effectively reduced by tilting the image plane. Numerical calculation shows that the maximum RMS radius of image plane is only 88.14 μm, the numerical aperture of image domain is 0.217, and all the design results meet the application requirements well.