The fixed-ordering illumination patterns lack an effective information interchange with objects. This leads to the light intensity values carrying random feature information, affecting the model's building and recognition capability. Furthermore, this method needs numerous illumination pattern projection counts, which results in low sampling efficiency. Therefore, we propose a new optimized-ordering illumination patterns method. In this paper, we first integrate fixed-ordering illumination patterns with category-representative images to obtain light intensity values that carry category feature information. Subsequently, the mechanisms of intra-category feature importance and inter-category feature differences are introduced to reorder the light intensity values and eliminate index numbers to generate an optimized-ordering index array. Finally, based on this index array, illumination patterns are extracted from the original fixed ordering method to form the new optimized-ordering illumination patterns. Experimental results show that in simulation experiments using the MNIST, Fashion MNIST, TRI, and Multi-category datasets, the optimized ordering method achieved recognition accuracies of 90.00%, 80.00%, 80.00%, and 80.00% with only 30 sampling times. Actual tests with physical objects such as mini numbers and clothing also confirmed these findings. The method offers a new research approach by enhancing recognition accuracy and sampling efficiency in single-pixel object classification.