The invention relates to an electric vehicle double-speed automatic transmission electronic control unit and a control strategy. The transmission control unit (TCU) comprises a single chip microcomputer, a power circuit, a pulse signal conditioning circuit, a Hall circuit conditioning circuit and a rotating speed signal frequency dividing circuit connected with a single chip microcomputer TIM module, a switching signal conditioning circuit and a motor direction control circuit connected with a single chip microcomputer universal I/O (Input/Output) module, an analog signal conditioning circuitconnected with a single chip microcomputer A/D (Analog-Digital) module, a one-way CAN (Controlled Area Network) communication signal conditioning circuit connected with a single chip microcomputer CANmodule, a PWM (Pulse-Width Modulation) drive circuit connected with a single chip microcomputer PWM module, a double-circuit SCI (Serial Communications Interface) communication signal conditioning circuit connected with a single chip microcomputer SCI serial port, a reset circuit and a crystal oscillation circuit. The universality, the reliability and the anti-interference of a hardware system are higher, so that a controller structure is more compact, the isolation communication and the on-line data modification of different types of signals can be realized, correct gear shift is ensured, the requirements on a dynamic property and economy of a whole vehicle are met, and the costs of a drive motor and a control system are reduced.