A simple and effective method for obtaining the uniformity information of films is proposed. The method is based on the accurate measurement method for nano film thickness we given before. It firstly measures the spectrum of the film in different positions on a substrate containing a transition layer and then obtains the uniformity information of the film according to the interference peak difference. Compared with the traditional method, this method reduces the error resulting from the direct measurement of film thickness. Therefore, it can obtain the uniformity information of the film quickly. The method is convenient and simple in operation and is of important value to the improvement of coating processes.