The detection of insulators in substation is completed by climbing the tower manually, which is high labor intensity and high risk. In this paper, the robot system of insulator live detection is proposed. The operator controls the robot system remotely on the ground. The conveying device and detection vehicle are used to place and retrieve the insulator detection end tool. The radar identifies and locates the insulator string and end tool. The end tool detects the resistance values of insulators piece by piece on the insulator string. The resistance values are transmitted wirelessly to the hand-held terminal for display and storage. The robot warns insulators with low or zero resistance. The laboratory test shows that the intelligent degree and accuracy of the insulator live detection robot are high.