Bearing plates installed at the bottom of the box girder in the compression zone at the pier-beam joint of the box-shaped composite rigid frame bridge can increase the compression area and avoid stress concentration and local buckling of the box girder bottom plate. The force transmission mechanism and applicability of bearing plate typed pier-beam joint are not clear. The design method of the joint construction is lacking. According to the verified solid finite element calculation model， the trial design of the box-shaped composite rigid frame bridge with bearing plates is conducted. The force transmission mechanism and load bearing ratio of the bearing plate typed pier-beam joint are analyzed. A calculation method of the internal force of the pier-beam joint is established， and a parameter analysis of the arrangement of bearing plates is carried out. Results indicate that， on the basis of determining the dimensions and material characteristics of the trial design， axial pressure and axial tension are mainly transmitted through the web plate of the girder， accounting for about 60% and 50%， respectively. The force transmission mechanism of bending moment action is similar to that of axial force. The shear force is mainly transmitted through the longitudinal stiffeners on the back side， accounting for about -80%； The shear force is mainly transmitted through the bearing plate on the same side， accounting for about 80%. The deviation between the theoretical calculation results and the finite element calculation results is less than 8.8%. The theoretical calculation can be applied to the internal force calculation of the bearing plate typed pier-beam joint. It is suggested that the relative transverse spacing should be 1/6 and the relative plate thickness should be 1 in the design of bearing plate. When the pier height exceeds 15 m， the beam-pier linear stiffness ratio is greater than 0.047， and the steel girder stress of the bearing plate typed pier-beam joint is less than that of the conventional pier-beam joint. When the pier height exceeds 30m， the steel girder stress at the pier-beam joint of the box-shaped composite rigid frame bridge can be significantly reduced by using the bearing plates.