A multi-channel device and method for measuring the distortion and magnification of objective lens. The multi-channel device for measuring the distortion and magnification of objective lens comprises an illumination system, a reticle stage, a test reticle, a projection objective lens, a wafer stage and a multi-channel image plane sensor, wherein the multi-channel image plane sensor simultaneously measures the image placement shifts between actual image points and nominal image points after a plurality of object plane test marks are imaged by the projection objective lens, and calculates the distortion and magnification errors of the objective lens by fitting, which shortens the measurement time, eliminates the influence of wafer stage errors on the measurement accuracy and improves the measurement accuracy.