An electric vehicle thermal management system is provided. The system includes an inside AC unit having an air inlet unit and an air outlet unit and a cooling core embedded therein. A heating core is disposed between the air outlet unit of the inside AC unit and the cooling core and a control door is disposed inside the inside AC unit to adjust air supply to the heating core. A first flow path circulates to pass through the heating core and includes an electric heater. A branch flow path is branched from downstream point of the heating core of the first flow path and passing through a high voltage battery heat exchange unit. A control valve is disposed in a branch point between the first flow path and the branch flow path and a second flow path circulates between a compressor and a condenser and the cooling core.