The present disclosure relates to a device for detecting a liquid crystal module and a method for detecting the quantity of liquid crystal. The method includes a cover for fixedly accommodating the liquid crystal module. An accommodation space for accommodating collision units is formed between the liquid crystal module and the cover, the collision units being connected to the top wall of the cover through elastic members. The collision units are spaced from the liquid crystal module in a certain distance in a static status, and collide with a panel of the liquid crystal module through vibration of the cover in the vertical direction during detection. The device for detecting a liquid crystal module improves the detection efficiency.