Abstract: The feasibility of producing superheavy nuclei in proton evaporation channels was systematically studied within the dinuclear system (DNS) model. Due to the Z = 114 proton-shell, one can synthesize Fl isotopes in proton evaporation channels. We only considered the case of evaporating one proton first and then n neutrons in this work, other cases were ignored due to the small cross-section. The production cross sections of unknown isotopes ^{290, 291}Fl in ³⁸S+²⁵⁵Es reaction are the highest compared with ⁵⁰Ti+²⁴³Np and ⁵⁴Cr+²³⁹Pa reactions, and the maximum cross sections are 1.1 and 15.1 pb, respectively. ⁴²S+²⁵⁴Es is a promising candidate to approach the island of stability as the radioactive beam facilities are upgraded in the future, and the production cross sections of ^291−294Fl in that reaction are estimated to be 3.2, 6.0, 4.0, and 0.1 pb, respectively.