A method for evaporation monitoring, the method for evaporation monitoring comprises: providing an evaporation mask , the evaporation mask comprising a first functional region and a first peripheral region disposed outside of the first functional region , the first functional region defining at least one first opening , the first peripheral region defining at least one second opening , wherein the second opening is configured to form a monitoring structure on the OLED panel by evaporation; providing an OLED panel , the OLED panel comprising a second functional region and a second peripheral region disposed outside of the second functional region , the second peripheral region having an observation layer formed thereon, wherein the observation layer is configured to facilitate an observation of the monitoring structure ; forming a functional layer and at least one monitoring structure on the second functional region and the observation layer of the OLED panel respectively using the evaporation mask ; acquiring an actual center of the at least one monitoring structure on the OLED panel ; and comparing the actual center of the monitoring structure with a theoretical center of the monitoring structure to obtain an evaporation effect of the at least one first opening of the evaporation mask , wherein the observation layer is made of a reflective material and has a color different from a color of the monitoring structure to ease a contour of the monitoring structure being captured by an image capturing device, characterized in that the observation layer covers an entirety of the second peripheral region ; and in that the actual center of the at least one monitoring structure is acquired in the following way: capturing the contour of the at least one monitoring structure by a camera or a video; and calculating the center of the at least one monitoring structure according to the captured monitoring structures. providing an evaporation mask , the evaporation mask comprising a first functional region and a first peripheral region disposed outside of the first functional region , the first functional region defining at least one first opening , the first peripheral region defining at least one second opening , wherein the second opening is configured to form a monitoring structure on the OLED panel by evaporation; providing an OLED panel , the OLED panel comprising a second functional region and a second peripheral region disposed outside of the second functional region , the second peripheral region having an observation layer formed thereon, wherein the observation layer is configured to facilitate an observation of the monitoring structure ; forming a functional layer and at least one monitoring structure on the second functional region and the observation layer of the OLED panel respectively using the evaporation mask ; acquiring an actual center of the at least one monitoring structure on the OLED panel ; and comparing the actual center of the monitoring structure with a theoretical center of the monitoring structure to obtain an evaporation effect of the at least one first opening of the evaporation mask , wherein the observation layer is made of a reflective material and has a color different from a color of the monitoring structure to ease a contour of the monitoring structure being captured by an image capturing device, characterized in that the observation layer covers an entirety of the second peripheral region ; and in that the actual center of the at least one monitoring structure is acquired in the following way: capturing the contour of the at least one monitoring structure by a camera or a video; and calculating the center of the at least one monitoring structure according to the captured monitoring structures. capturing the contour of the at least one monitoring structure by a camera or a video; and calculating the center of the at least one monitoring structure according to the captured monitoring structures. <EOS>