Abstract: The disclosure provides a compensating design method for a shadow mask including: providing a first shadow mask having a first opening pattern and a first material pattern; disposing the first shadow mask on a substrate having a predetermined depositing film area with first and second sides; performing a deposition process by using the first shadow mask as a mask to form a film on an actual depositing film area, wherein the distance between the first and the third sides is a first bias, and the distance between the second and the fourth sides is a second bias, and a single side gray zone of the actual depositing film area relative to the predetermined depositing film area is substantially half of the sum of the first and the second biases; and designing a second shadow mask according to the single side gray zone.