A light spot arrangement, a surface profile measuring method and a method for calculating control data for an exposure field are disclosed. The light spot arrangement includes a plurality of measuring light spots (100) which define at least one set of orthogonal line segments, wherein the measuring light spots (100) lying on the orthogonal line segments radiate outward from a center, with each of the orthogonal line segments defined by at least four measuring light spots. With this light spot arrangement comprising at least one set of orthogonal line segments defined by measuring light spots radiating outward from a center, readings of multiple ones of the light spots (100) can be acquired in real time, and exposure can be performed with real-time focusing and leveling based on a surface profile of the wafer (200) derived from a surface fitting process carried out on the readings.