The craft technique of timber arch bridge building. Timber arch bridge is composed of bridge abutment, bridge body (including arch frame and bridge floor) and bridge house. There are single arch bridges, double arch bridges, and multiple arch bridges. Bridge body looks like a rainbow, so it is also called rainbow bridge. The whole working procedure includes selecting address for the bridge, building the bridge abutment, level measurement, building the bridge house, and making the shrine and weatherproof boards. In June 7th, 2008, the craft technique of timber arch bridge has been listed in the second batch of State-level Intangible Cultural Heritage List.