The invention provides a control device used for intelligent connection between a motorcar chassis and a conveying machinery and a control method thereof. The technical proposal is that the control device comprises a socket connector, a chassis CCU unit, a frequency convertor, a programmable microcontroller, an analog quantity isolator, an intermediate relay and an external accelerator, wherein, the output end of the chassis CCU unit is connected with the frequency convertor by the socket connector, the frequency convertor is connected with the programmable microcontroller which is respectively connected with the analog quantity isolator and the intermediate relay, and the analog quantity isolator is connected with the external accelerator by the socket connector. The invention provides the method that the programmable microcontroller firstly acquires the value obtained by dividing engine speed signals and transmission shaft rotating speed signals, and then judges the gear; the set value of the rotating speed can be obtained according to the gear; finally, the rotating speed is regulated according to the set value. The invention has the advantages that the interface of the socket connector unifies the connection of different chassises and brings convenience for connection and maintenance, thus improving the efficiency, reducing the using cost and lightening the labor intensity of the workers.