The invention provides a capillary tube sampling system and method and a single-cell electrical characteristic detection system. The capillary tube sampling system comprises an injection pump, a capillary tube, a micro-fluidic chip and a negative-pressure module, wherein a compression channel, a cell recovery channel and a negative-pressure channel are sequentially formed in the micro-fluidic chip and constitute a micro-channel of the micro-fluidic chip; the front end of the compression channel is taken as a liquid inlet of the micro-channel, the rear end of the compression channel is connected to a liquid outlet of the micro-channel through the cell recovery channel and the negative-pressure channel, and the negative-pressure module is connected to the liquid outlet of the micro-channel; the rear end of the capillary tube is connected to the injection pump, inhalation and discharge of a cell suspension are controlled by the injection pump, and the cell suspension dropped in from one side of the liquid inlet of the micro-channel by the capillary tube sequentially enters the compression channel and the cell recovery channel under the action of the negative pressure provided by the negative-pressure module. According to the capillary tube sampling system and method and the single-cell electrical characteristic detection system, the loss rate of samples can be effectively reduced, the high recovery rate can be realized, and the single-cell electrical characteristic detection system can be used for electrical characteristic detection of cell samples with extremely small quantity of cells.