The alkaline electroplating bath formulation of bismuth was developed. The optimal composition formula was obtained by an orthogonal method as follows: bismuth nitrate 60g/L,disodium ethylene diamine tetraacetate(EDTA) 90g/L, 5-sulfosalicylic acid 120g/L, potassium sodium tartrate 60g/L, potassium chloride 60g/L. The influence of bismuth content on the rate of bismuth film and complexing agents on the impact of cathode polarization was studied. The surface roughness, microstructure and adhesion strength of bismuth film was detected. It was the result that the bismuth film has the features of fine and uniform grain, good smoothness, good adhesion and bright color.