An apparatus and a method for detecting presence of attenuation in the OLED device are provided. The apparatus for detecting presence of attenuation in the OLED device includes: a difference function construction circuit, an integrating circuit, a comparing circuit and a determining circuit. The method for detecting presence of attenuation in the OLED device includes: constructing a first light brightness difference function and a second light brightness difference function before and after aging, integrating the first function and the second function, comparing two integrals, and determining whether or not intrinsic attenuation is present in a light emitting material of a light emitting layer in the OLED device. The apparatus for detecting presence of attenuation in the OLED device is configured for executing the method for detecting presence of attenuation in the OLED device.