The straight-shock internal flows with various wall boundaries are generated by solving the Taylor-Maccoll equation and combining the method of characteristics. Employing the geometric relation in the osculating-cone method, the planform-customized waverider design is developed using the straight-shock internal conical flows. The different wall boundaries of the internal flows correspond with the different pressure distributions along the walls. When the wall boundaries varied from the elevated to descend profile, the pressure along the wall changed from the increasing to decreasing distribution. Taking the 3D leading edge of one double swept waverider with wing dihedral as the baseline planform shape, the planform-customized waveriders using the internal conical flows with different boundaries are designed. Then the effect of the internal flows on the waverider performance was analyzed. Results shows that the planform-customized waveriders generated from the internal flows with different wall boundaries featured high lift-to-drag ratio. The shock wave positions in their flow fields were nearly identical, indicating promising wave-riding perfor-mance. When the wall boundaries of the basic internal flows varied from elevated to descend profile along the axial coordinate, the pressure of the lower surface transitions from increasing to decreasing. The compression ability under the lower surface also decreased, but the total pressure recovery coefficients remains similar. In addition, as the wall boundary approached a straight line more closely, the flow uniformity under the lower surface of waveriders are better, just like that of the basic internal flows.