A method of measuring sensor chip shift comprises the following steps. First, provide a contact image sensor module comprising a plurality of sensor chips arranged in a row on a main board, with each sensor chip having multiple sensors. Next, provide a test chart with a predetermined pattern. Further, enable the multiple sensors of the contact image sensor module to scan the predetermined pattern of the test chart. Moreover, select signal waves sensed by the sensors at the ends of two adjacent sensor chips. Finally, calculate the gap between the sensors at the ends of the two adjacent sensor chips according to the signal waves.