The invention discloses a piecewise sliding contact line power supply connection device which has a simple structure, is simple and easy to operate, safe and reliable, and low in cost, and can realize the piecewise sliding contact line power supply connection method. The piecewise sliding contact line power supply connection device is arranged at the fracture part of a fixed sliding contact line and a movable sliding contact line or the fixed sliding contact line and a maintenance sliding contact line, and comprises a copper bar, amounting bracket, a decelerating transmission mechanism, a motor and a control box, wherein the mounting bracket is mounted and fixed on the mounting surface, the decelerating transmission mechanism is mounted and fixed on the mounting bracket, and the copper bar is connected with the decelerating transmission mechanism; the motor is mounted and fixed on the mounting bracket, and the motor is connected with the decelerating transmission mechanism; the control box is electrically connected with the motor to control the motor to rotate; the motor drives the copper bar to move upwards and downwards in the vertical direction through the decelerating transmission mechanism, so as to realize connecting or breaking off the electrical connection of two piecewise sliding contact lines safely and reliably.