In the on-orbit images of the SDGSAT-1 TIS, there are image striping phenomena caused by the nonlinear response of the detector and flickering effects caused by the detector’s jump response. Based on the characteristics of the SDGSAT-1 TIS, a detection method for anomalous pixels using time-domain gradients and nonlinearity is proposed. This method also includes adaptive threshold adjustment and on-orbit data detection based on scene images. The results show that in each band, the number of flickering pixels with a detection probability exceeding 95% is fewer than 7, and the relative positions of these flickering pixels in the images are fixed. Additionally, traceability analysis of the on-orbit radiometric data reveals that the noise deviation of flickering pixels is more than 10% greater compared to normal pixels. This indicates that the flickering behavior is not random and that these pixels are more prone to flickering than others. In each band, the number of nonlinear-response pixels with a detection probability exceeding 95% is fewer than 6. Additionally, a traceability analysis of on-orbit radiometric data shows that the response deviation of nonlinear-response pixels is more than 0.7% compared to normal pixels. This result indicates that the occurrence of nonlinear-response pixels on orbit is not random and provides a new approach for early detection of anomalous pixels based on on-orbit radiometric data.