Liaojiaxi railway bridge is the key node of Chongqing Rail Transit Line 15 in China. The concrete beam-steel arch composite rigid frame system is innovatively adopted, that is, the conventional prestressed concrete continuous rigid frame is combined with the deck type steel arch to form an open-web main girder composed of upper chord concrete beam and lower chord steel arch rib, which can overcome the disadvantages of long-term deflection and web cracking of conventional long-span concrete rigid frame bridge. The upper and lower chords of the main bridge are constructed by the hanging basket balanced cantilever method. Due to its small section size, the cable-stayed suspension system is used to assist the structural force during the construction period in order to better control the line shape. Based on the conventional diamond hanging basket, the crane system is added to form an integrated construction equipment, which realizes the synchronous operation of cantilever concrete pouring and arch rib assembling in the narrow space. A special temporary locking device for the upper and lower chord closure section is developed, which is well adapted to the deformation differences caused by temperature, shrinkage, creep, and other effects in steel-concrete structures. Practice has proven that this new bridge type has significant technical and economic advantages in the span range of 200–400 m, and has promotion and application value.