The effect of electrolyte's surface tension on Ni-Fe codeposition for MEMS application was studied. A nickel-iron microstructure was obtained inside high-aspect-ratio (210 mum deep with 7mum width) microchannel. The internal stress and surface defect of the alloy microstructure are influenced by the presence of surfactant and applied current. Uniform distribution of deposit inside microstructure can be achieved by choosing proper current, surfactant and optimal control of hydrogen evolution reaction which can induce agitation and mitigate pH variation during electrodeposition.