Based on the advanced frequency conversion method to test the volt ampere characteristic curve of CT, the maximum output is only 180V AC voltage and 12a AC current, but it can cope with the CT test with the inflection point as high as 30KV. It has comprehensive functions and can meet the steady-state or transient characteristic tests of excitation, transformation ratio, phase, polarity, secondary winding resistance, load, ratio difference and angle difference of all types of CT (including high inflection point, large transformation ratio and transformer bushing CT). CT can be tested and analyzed according to gb20840, gb1208 (iec60044-1), gb16847 (iec60044-6) and other standards, and automatically give inflection point voltage / current, 10% error curve, 5% error curve, accuracy limit factor (ALF), instrument security factor (FS), secondary time constant (TS), remanence coefficient (KR), accuracy level, saturated and unsaturated inductance and other parameters. The angle difference and ratio difference of CT under 1%~120% rated current and different loads can be obtained by only one comprehensive test. The test results can also be extended to other current ranges and loads. It can test the actual load and power factor of the transformer. It can complete excitation test, transformation ratio test and polarity check of electromagnetic Pt. Friendly and beautiful interface, all Chinese graphical interface, 5.7-inch graphic transparent LCD, visible in the sun. Using the rotating mouse operation, the operation is simple, fast and convenient, and easy to master. The device can store 1000 groups of test data without losing power. It can be exported through USB flash disk at any time, and historical data can also be retrieved for analysis and comparison. The upper computer software is presented to generate word format test report, and the functions of variable parameter analysis, cursor reading and curve ratio are realized. The equipment is portable, and the panel is equipped with a printer, which can automatically print the generated test report.