The present invention publishes a conversion adaptor used for LCD panel inspection. The conversion adaptor comprises in order: a first connector plug, an adaptor main body, and a second connector plug; wherein, the first connector plug is used to connect to the connector of a test signal source, and the second connector plug is used to connect to the connector of a connecting cable to an LCD device. The present invention also includes an LCD inspection system. By adding a conversion adaptor, the present invention prevents damage done to the test signal source caused by frequent plugging and unplugging of LVDS cables from its external connector.