The invention provides a liquid crystal panel detection device and a liquid crystal panel detection method. The device comprises a signal input module used for providing display signals and variable public electrode voltage signals of a liquid crystal panel to be detected, a detection module used for detecting the area to be detected of the liquid crystal panel to be detected when the signal input module inputs different public electrode voltage signals so as to obtain brightness detection data of the area to be detected under different public electrode voltage signals, and a detection platform used for bearing the liquid crystal panel to be detected and controlling the detection module to be moved to the area to be detected. In the detection device, the detection module can move on the detection platform so as to detect the brightness of the liquid crystal panel at any area on the horizontal plane, and the situation that the brightness blink is variable along with the public electrode voltage is obtained by adjusting the public electrode voltage of the liquid crystal panel so as to provide a judgment evidence for distinguishing between uneven electrical display and uneven non-electric display.