On the basis of the cracking desulfurization of naphtha and the subsidiary riser in the fluid catalytic cracking (FCC) process for gasoline reformation, the in situ sulfur removing from naphtha in the FCC unit was investigated and a conceptual process was proposed. The relevant experiments were conducted in a confined fluidized bed reactor (CFB) and a technical pilot scale riser (TPSR) FCC apparatus. The effects of operation conditions such as temperature, catalyst-to-oil ratio, and weight hourly space velocity on product distribution and sulfur reduction of the recycled FCC naphtha were researched in the CFB reactor, and the optimal conditions were determined. The hydrogen transfer reaction aiming for sulfur removal was quantitatively analyzed. Results indicated that higher hydrogen transfer activity and proper cracking ability was beneficial to reduce the sulfur content of gasoline. The TPSR experimental results showed that sulfur concentration of the naphtha in the conceptual process decreased from 426 to 139 mu g.g(-1), with a 67.37% reduction compared to that of the routine FCC process. No obvious changes in light oil yield and liquid product yield were observed except a small increase in coke yield.