Abstract: The non fullness of the grouting of pre-stressed bridge pore allows rapid loss of the pre-stresses, shortening life of the bridge. Initial inspection and re-examination using the method of combining through-elastic wave penetrate method, ultrasonic test and scanning shock echo method to test the grouting density of pre-stressed duct, assess duct grouting quality and locate defects, and further take related remedial measures. All these measures lead to control the grouting quality and ensure the pre-stressing effect. The test results and analysis proved that the relying on the combination of nondestructive testing technology and initial inspection and rechecking method is convenient, accurate and feasible.