Abstract: The present invention discloses a quick charging data line of a USB interface, comprising: a boosting module arranged between a host end of a USB data line connected with a primary device and a slave end connected with an assistant device; and a mode switching module that realizes power supply through the boosting module, wherein after boosting the voltage of the power supply end of the host end of the USB data line from 5V to 5.1-5.4V, the boosting module is connected with the slave end; the mode switching module at least comprises a control module for controlling the magnitude of output current, wherein the control module can control the magnitude of charging current inputted into the slave end through a port of the control module; and the mode switching module also comprises an LED output portion which can realize button input of mode selection and can prompt the current operating mode of the data line for a user.