Chinese Giant Solar Telescope (CGST) is the next generation infrared and optical solar telescope of China, which is proposed and pushed by the solar astronomy community of China and listed into the National Plans of Major Science and Technology Infrastructures. CGST is currently proposed to be an 8 meter Ring Solar Telescope (RST) with width of 1 meter, the hollow and symmetric structure of such an annular aperture facilitates the thermal control and high precision magnetic field measurement for a solar telescope. Adaptive optics (AO) is an indispensable tool of RST to obtain diffraction limited observations. How to realize AO involved wavefront sensing and correcting, and the degree of compensating in a narrow annular aperture is the primary problem of AO implementation of RST. Wavefront reconstruction involved problems of RST are first investigated and discussed in this paper using end to end simulation based on Shack-Hartmann wavefront sensing (SHWFS). The simulation results show that performance of zonal reconstruction with measurement noise no more than 0.05 arc sec can meets the requirement of RST for diffraction-limited imaging at wavelength of 1μm, which satisfies most science cases of RST in near infrared waveband.