The invention discloses a system and method for measuring floating basin type insulator surface charges.The system mainly comprises a shell, a floating measurement base frame, a vertical direction adjusting knob, a rotary support frame, a rotation driving servo motor, an optical calibrator, a radial moving mechanism driving servo motor, an axial moving mechanism driving servo motor, a basin type insulator, a measuring head, a measuring head attitude driving servo motor, a support, a ball cabin and a horizontal direction adjusting knob.By means of the system, the basin type insulator surface charges can be measured without disassembling a tank, the amount of SF6 gas required by a test is greatly saved, and test cost is lowered; the position of the measuring head is adjusted by controlling the driving servo motors in different directions, it is guaranteed that all positions of the basin type insulator can be measured, and the system and method for measuring the floating basin type insulator surface charges have the advantages of being high in accuracy, easy and convenient to operate and the like.