The combined pin composite beam eliminates the steel top plate and the welding nails on it of the conventional composite beam. The steel web is cut into a certain shape and then embedded in the concrete, which makes the steel and concrete form a combined pin connection. This new precast composite beam structure is conducive to enhancing the industrialization level of bridges. Therefore, the technical development of combined pin composite beams at home and abroad is summarized firstly. And then the innovative design of combined pin composite beams for the ramp bridges in Zhonghuan Town of Quanzhou is introduced. The standard span of the ramp bridges in Zhonghuan Town of Quanzhou is 30 m, the structures are simply supported, the bridge deck is continuous, and the four-span per unit is adopted. The total bridge width is 8.5 m. The four-girder structure is used. The composite beam is 1.6 m high. The steel girders are made of Q345C, and the deck slabs are made of C50. The transverse deck slabs and two steel longitudinal girders are firstly formed into the π-shaped prefabricated composite beams on site, which are respectively hoisted onto the pier top, and then connected by a 0.25 m wide UHPC longitudinal wet joint. Due to the elimination of the middle crossbeam and web stiffening settings, the steel consumption of the composite beam is only 148 kg/m², which not only reduces the engineering cost, but also facilitates the construction and later maintenance.