Stress and strain test technology is the common use of the crane structure strength of static,dynamic check test methods,Used in the structure stress level and intensity reserve calculation.For structure damage detection research and application is less,the lack of feasible technical standards,operation method and damage index..Taking an example of a 75t-QD bridge crane for structure damage evaluation on stress-strain tests.Discusses structure damage stress-strain testing operation method and evaluation index,For the stress-strain test technique application in structure damage to provide a reference.