Fe41Co7Cr15Mo14C15B6Y2 bulk amorphous alloys and amorphous coating alloys were prepared to investigate the effects of density difference on corrosion resistance by analyzing the relative surface work function of samples before and after chemical corrosion. The role of porosity in the corrosion process was determined by analyzing the electrochemical corrosion characteristics of coating and bulk alloys in a 0.5 mol/L H2SO4 solution based on driven potential polarization curves and AC impedance measurement. The results show that the corrosion potential of bulk amorphous alloys is higher than that of coating alloys, with a current value one order of magnitude smaller, and the fitting circuit of bulk alloys is of the R(QR) type. Due to factors such as porosity and surface passivation films, the fitting circuit of the coating alloys is of the (R(Q(R(QR)))) type. Electron probe experimental results show that the porosity difference between coating and bulk alloys is 9.25%, leading to a work function difference of 50 meV. Larger and more numerous pores lead to worse corrosion resistance. Both before and after corrosion, the work function of the bulk amorphous alloy is higher than that of the coating alloys, showing that the bulk amorphous alloy has stronger corrosion resistance.