Abstract: Bolted shear connector is one of the basic elements to realize the demountable function of prefabricated steel-concrete composite members. To solve the problem of inadequate deformability of the bolted shear connector, a high-deformability plug-type bolted shear connector (PTBSC) was proposed. The experimental studies and finite element analyses show that the shear-slip relation curve of a PTBSC is bilinear, with significant yield strength and ultimate strength. The development of evaluation methods for yield strength and ultimate strength of a PTBSC is required. A theoretical formula for the PTBSC yield strength was derived and verified by comparing to the corresponding finite element analyses results. The effect of parameters included in the theoretical formula was analyzed. The PTBSC yield strength increases by increasing bolt diameter and bolt strength grade. The yield strength reduces by increasing the slenderness ratio of bolt shank. Increasing the compressive strength of the infilled-plug material can also improve the PTBSC yield strength. When the strength is greater than 100 MPa, the yield strength basically remains unchanged. The PTBSC ultimate strength is proposed by employing a calibrated empirical equation, using the PTBSC finite element analyses results. When the ultimate strength is 0.7 times of the ultimate tensile strength for a PTBSC bolt, the error is within 20%. Therefore, the PTBSC ultimate strength can be well predicted with certain margin of safety.