Light shield capable of improving aerial image alignment checking precision degree and photolithography method

The present invention provides a light cover and a lithography method used for the improvement of space imaging overlay test accuracy. Phenomenon of a wider and uneven slope of edge of photoresist which supports a space imaging overlay marked graphics caused by low graphic density of the space imaging overlay marked graphics and low temperature of pre-baking technique exists in the light cover of the prior art, and the phenomenon can not be thoroughly improved by single-layer auxiliary strips arranged on the circumference of the space imaging overlay marked graphics. A plurality of layers of the auxiliary stripes for increasing the graphics density are respectively positioned on the circumference of the space imaging overlay marked graphics arranged inside the light cover of the present invention. The lithography method of the present invention has the coating of the photoresist firstly, then pre-baking technique with a temperature range from 115 DEG C to 125 DEG C, exposure technique by using the light cover