Disclosed is a method for measuring the brightness non-uniformity of a display panel, which is improved to express the brightness non-uniformity numerically. The disclosed method for measuring the brightness non-uniformity of a display panel comprises the steps of: setting by calculating a tone variation rate for the whole tone wedge of the measurement target range of a panel; measuring the brightness of the whole pixels of a certain tone of the panel to calculate the brightness average value of the whole panel of the certain tone; and quantifying by counting the number of the pixels having the brightness over the tone variation rate based on the average value and expressing the brightness non-uniformity with the number of the pixels. With the method, the brightness non-uniformity of a panel can be measured and expressed numerically and accurately, thereby objectively evaluating the degree of non-uniformity to set an appropriate processing standard corresponding to the degree. [Reference numerals] (S1) Select a target range of a panel; (S2) Measure a brightness value in the whole tone range for the target range of the panel; (S3) Calculate a first tone variation rate; (S4) Measure a brightness average value for a certain tone; (S5) Count the number of pixels having the brightness value over the first tone variation rate; (S6) Display brightness non-uniformity with the number of counted pixels