Abstract: In pulsed thermography testing, thermographic signal reconstruction(TSR) is used to analyze and process experimental results. The method can increase the spatial and temporal resolution of the thermographic sequence, increase signal to noise ratio, and reduce the amount of data. In addition, this method can eliminate the interference of certain pseudo-defects, such as pseudo-defects caused by the reflections of pulsed flash lamp and the camera lens. However, TSR is based on the polynomial curve fitting of temperature curve in which the polynomial order and data length influence the fitting result, and in some cases it may generate pseudo-defects in the infrared image. This article described the principle of TSR, and analyzed the pseudo-defects caused by TSR based on the experimental results that the specimen surface was in a state of thermal imbalance and non uniform surface.