A new Infrared Thermal Wave Nondestructive Testing technology—laser scanning thermography nondestructive testing technology was investigated in this work. A finite element simulation model was built based on the deeply analysis of detection mechanism, and the temperature difference between defect and non-defect was selected to analyze the influence rules of the key parameters such as sample material, defect size, defect depth, laser scanning speed and laser scanning power on laser scanning thermography nondestructive testing technology, which provided a reference for the further development and application of the new technology. The relationship between the parameters and the maximum surface temperature difference were numerically investigated. On this basis, the control strategy of detection parameter in the laser scanning thermography nondestructive testing technology was put forward, which can facilitate to set the detection parameters quickly and accurately for the corresponding defect characteristics of sample in actual detection process, and to improve the detection ability.