The invention relates to a detecting device for an electric energy meter automatic verification assembly line. The detecting device includes a tray which is fixedly provided with a stand, and a standard verification device positioned on the stand; a left side plate and a right side plate of the stand are provided with at least one groove respectively; wiring ports are positioned in the grooves; an input connection terminal and an output connection terminal of the stand verification device are connected to the corresponding wiring ports. The invention also discloses a quality monitoring method for the detecting device of the electric energy meter automatic verification assembly line. According to the invention, the problem that whether instruments of a verification unit can normally operate under a heavy load working condition or not can be effectively solved, manual verification is not required, and the time and the effort can be saved; the detecting device can enter an assembly line without pause of the assembly line, verifie the verification unit, determine whether metering performance of the verification unit is normal or not, and timely notice a maintainer to process the problem if the metering performance of the verification unit is abnormal, so that various data of a verification link is accurate and reliable.