Open-loop hall current transformer and closed-loop hall current transformer suffer the problem of magnetic saturation in the presence of magnetic core. A current measurement system based on Hall effect element array was developed, including the Hall effect sensor array and the electronic circuit. The circular array is composed of a surge of Hall element to approximate integration, the measured current can be calculated by measuring the magnetic flux density induced by primary conductor. The mathematic module of the array was formulated, and the error variation in the case of eccentric was investigated. Afterwards the electronic circuit composed of the weighted gain adjustment circuit, the phase shift circuit and the power amplifier circuit was deigned to output high power signal. Finally, the basic error testing and the location influence experiment were performed. The results validate that the designed system can meet the requirement of 0.2 accuracy class. The designed system comprises 16 Hall element, additionally, current ratio of the system is 600A/5A and the power consumption is only 0.4W.