A thin-layer electrolytic cell for reflective visible spectra is designed and made.A bright Pt-flake (as the working-electrode), a Pt-wire (as the auxiliary electrode) and a Ag/AgCl electrode (as the reference electrode) are assembled in this cell.The thin-layer of solution is controlled by plastics backing ring between the bright Pt-flake and the glass-flake.Its volume approximated 16 μL when its thickness was 0.2 mm.Because of using parallel reflective path, the incident light and the exit light are kept in a line.It is applicable to various visible spectrophotometers without the change of its light path.Its quality in the system of K3Fe(CN)6/K4Fe(CN)6 is tested by cyclic voltammetry and in-situ potentiostatic spectrophotometry.This cell has good thin-layer spectroelectrochem. performance, and is able be used for research of thin-layer visible spectroelectrochem.