The invention relates to a cost control intelligent electric energy meter payment function reliability test device and a test method. The test device comprises a power module, a control module, a display module, a keyboard, a drive module, an adjustable voltage module and an adjustable current module, wherein a controller is in electric connection with a power supply, a display, the keyboard and the drive module; the drive module is connected with the adjustable voltage module and the adjustable current module; and the adjustable voltage module and the adjustable current module are respectively connected to a voltage input terminal and a current input terminal of an electric energy meter, and voltage output and current output of a voltage regulator are adjusted according to parameters of the electric energy meter. The payment reliability is tested before the cost control intelligent electric energy meter accesses a network, and the batch of electric energy meters with a problem of 'minus amount jump' are subject to software upgrade. The operating cost of a power grid company is greatly reduced, the normal power utilization of a user is ensured, and economic losses and adverse social impacts to the user can be avoided.