A dynamic illumination design method based on LED array is proposed. First, the position of the LED array unit is selected and the target illumination distribution pattern is uniformly sampled. The illumination distribution matrix of each unit of the LED array is established. Then, the least square mathematical model of non-negative constraint is constructed and solved, and the non-negative weight distribution of each element of LED array is calculated. After applying the weights to the LED array, the LED array can approximate a specified illumination pattern within the target region. Based on the LED array, a series of examples are given to form complicated multiple-rings pattern and spiral pattern within the circular and rectangular target regions respectively. The root mean square (RMS) fitting error between the simulated illumination pattern and the target illumination pattern is less than 20% for all the designs, and the minimum RMS fitting error is less than 10%.