An electric motor, comprising: a motor rotor; and a motor stator comprising: a stator core having a plurality of stator teeth spaced along a circumferential direction of the stator core, two adjacent stator tooth defining a stator slot; a plurality of coil groups, each of the plurality of coil groups comprising a plurality of coils wound on the stator teeth, and an incoming line terminal and an outgoing line terminal both composed of a same number of coil end; first and second motor lead groups, wherein each of the first and second motor lead groups comprising a plurality of motor leads connected with coil ends of the coil groups and a motor control circuit, a total number of the motor leads of each of the first and second motor lead groups being equal to a number of coil groups, and each motor lead being connected to one incoming line terminal or one outgoing line terminal of one corresponding coil group; the motor stator further comprising first and second plug connectors; the plurality of motor leads of the first motor lead group are connected with the motor control circuit through the first plug connector; and wherein the plurality of motor leads of the second motor lead group are connected with the motor control circuit through the second plug connector; characterized in that: the electric motor satisfies a relationship: 5.18×10 -7 ≤T×Di -3 ×TPV -1 ≤1.17×10 -6, T is a rated torque of the electric motor with a unit of N·m, Di is a minimum inner diameter of the stator core with a unit of mm, TPV is a torque per unit volume of the motor rotor with a unit of kN·m·m -3, and TPV is greater than or equal to 5kN·m·m -3, and less than or equal to 45kN·m·m -3. a motor rotor; and a motor stator comprising: a stator core having a plurality of stator teeth spaced along a circumferential direction of the stator core, two adjacent stator tooth defining a stator slot; a plurality of coil groups, each of the plurality of coil groups comprising a plurality of coils wound on the stator teeth, and an incoming line terminal and an outgoing line terminal both composed of a same number of coil end; a stator core having a plurality of stator teeth spaced along a circumferential direction of the stator core, two adjacent stator tooth defining a stator slot; a plurality of coil groups, each of the plurality of coil groups comprising a plurality of coils wound on the stator teeth, and an incoming line terminal and an outgoing line terminal both composed of a same number of coil end; first and second motor lead groups, wherein each of the first and second motor lead groups comprising a plurality of motor leads connected with coil ends of the coil groups and a motor control circuit, a total number of the motor leads of each of the first and second motor lead groups being equal to a number of coil groups, and each motor lead being connected to one incoming line terminal or one outgoing line terminal of one corresponding coil group; the motor stator further comprising first and second plug connectors; the plurality of motor leads of the first motor lead group are connected with the motor control circuit through the first plug connector; and wherein the plurality of motor leads of the second motor lead group are connected with the motor control circuit through the second plug connector; characterized in that: the electric motor satisfies a relationship: 5.18×10 -7 ≤T×Di -3 ×TPV -1 ≤1.17×10 -6, T is a rated torque of the electric motor with a unit of N·m, Di is a minimum inner diameter of the stator core with a unit of mm, TPV is a torque per unit volume of the motor rotor with a unit of kN·m·m -3, and TPV is greater than or equal to 5kN·m·m -3, and less than or equal to 45kN·m·m -3. the electric motor satisfies a relationship: 5.18×10 -7 ≤T×Di -3 ×TPV -1 ≤1.17×10 -6, T is a rated torque of the electric motor with a unit of N·m, Di is a minimum inner diameter of the stator core with a unit of mm, TPV is a torque per unit volume of the motor rotor with a unit of kN·m·m -3, and TPV is greater than or equal to 5kN·m·m -3, and less than or equal to 45kN·m·m -3.