Abstract: Using the traditional technique to measure laser facula with a detector array, the array should be large enough if the facule has a large size, Thas large amount of detectors are needed which increase the cost. The design of rotational device of array detector makes it possible for measuring laser facula with high spatial resolution and low cost. The main idea is to rotate a linear array of detectors to carry out the facula measurement in the scanned area. The developing routine of the device and its measurement result is presented.