In order to investigate the degradation of critical current (Ic) in the Ag alloy sheathed Bi-2223 tapes due to a transverse compressive stress introduced during manufacturing and operation of the HTS systems, a sample holder consisting of the upper block made of Ti alloy and the lower support plate made of glass fibre reinforced plastic was prepared. A shorter spacing of voltage taps caused large degradation of critical current with respect to compressive stress. It was found that the extent of the Ic degradation is proportional to the initial critical current density of the tapes. Through the experiment optimizing the shape of voltage terminals and the pressing load for the continuous contact type 4-probe Ic measurement system, it was found that the conical shape tip with large curvature radius was effective in suppressing the Ic degradation in Bi-2223 tapes during the Ic measurement. A hard alloy sheath of Ag–0.6wt%Mn was found to be quite tolerant to the Ic degradation against the pressing load of voltage terminals.