Building outer wall defect detection method and system

The invention provides a building outer wall defect detection method and system, and belongs to the technical field of defect detection.The method comprises the steps that stress waves are applied to the surface of a to-be-detected building, and distribution of a stress wave field is calculated based on reflection and transmission coefficients of stress wave response signals; calculating a key defect expansion displacement model through the distribution of a stress wave field, and constructing a defect identification objective function; and iteratively updating the total defect identification target function to minimize the total defect identification target function until the convergence precision is reached, thereby obtaining the information of the key defects in the building exterior wall to be detected. According to the method, the purpose of defect detection according to the influence of the material of the building outer wall on stress wave propagation is achieved, and compared with an existing detectio