Abstract: A new leakage detection system based on high voltage DC method was successfully developed through comparison among foreign methods used in landfill leakage detection. The system uses CAN bus technology and successfully shoots the difficulties of massive data collection and long distance transmission caused by spreading detection area. The low-frequency pulse powering mode is applied and the data collected when supply power is positive and negative are subtracted, which greatly reduces the background noise. Through setting up reasonable earth-electricity model, the distribution problem of electrical potential in uneven medium is resolved and system detection accuracy is improved. The field tests show that the probability of detection error over 0.4 m is no more than 10% , when the space between detection electrodes is 4 m.