Abstract: The reinforced concrete double arch bridge with the common length of 140 m has been used formore than 35 years.Parts of the structure have been damaged due to growing axial load and lower designed load etc.With the increase in traffic load, it is indire need of the confirmation that the bridge can bear the heavy load and meet the safety requirement or not.By means of nondestructive detection the overall health inspection for the whole structure is carried out.Based on the data obtained, the work condition of the bridge and the load capacity are evaluated.The conclusion is that many parts of the bridge need to be repaired and the measure to streng then the arch bridge is suggested.For there are many double arch bridges needed to be checked and assessed at middle age in west China, the method given in the paper can be employed as a reference for the sim ilar work.