The invention discloses a remote speech control system used in a construction machinery. The system is connected with a master controller of the construction machinery. The system comprises a speech reception device which receives speech signals and converts the received speech signals into analog electrical signals; a wireless signal transmitter installation transmits the analog electrical signals to a wireless signal reception device at the far end which converts the analog electrical signals into digital signals; a speech recognition device searches speech simulation signals corresponding to the digital signals in a built-in database; a control command reforming unit searches and transmits control commands corresponding to the speech imitation signals to the master controller of the construction machinery. The invention also discloses a remote speech control method used in the construction machinery. The remote speech control system and the method thereof are used for realizing thespeech control on the construction machinery.