The invention discloses a method for controlling a mechanical arm based on arm action. The method comprises the following steps: 1, converting attitude information of a key degree of freedom of the arm into an amplitude value of analog voltage through a sensor; 2, sampling and quantifying an analog signal through an Arduino controller, and converting a quantified value into a rotating or bending angle of the key degree of freedom of the arm; 3, converting the rotating or bending angle value into a parameter of a steering engine control instruction through the Arduino controller; 4, sending the complete steering engine control instruction to a Bluetooth sending module through a serial port via the Arduino controller, and modulating a baseband signal via the Bluetooth sending module to transmit a modulated signal into a space through an antenna; 5, demodulating the modulated signal via a Bluetooth receiving module, and then transmitting the demodulated signal to a steering engine controller through a TTL communication serial port, wherein the steering engine controller controls a corresponding steering engine to rotate according to the steering engine control instruction so as to complete simulation of the arm action.