The invention discloses a wireless monitoring and early warning system of cable tension and compass signals in offshore oil extraction operation. The system comprises an FPSO (Floating Production Storage and Offloading) stopping oil storage barge and an unfixed oil extraction ship; a cable is connected between the FPSO stopping oil storage barge and the unfixed oil extraction ship; a compass instrument, a tension sensor used for detecting the cable tension, and a signal collecting and emitting integrated machine are arranged on the FPSO stopping oil storage barge; a wireless signal receiving terminal is arranged on the unfixed oil extraction ship; the signal collecting and emitting integrated machine is used for collecting compass signals of the compass instrument and tension signals of the tension sensor and sending the signals to the wireless signal receiving terminal; and the wireless signal receiving terminal is used for performing real-time monitoring and early warning according to the tension signals and the compass signals. The system realizes the real-time monitoring to the cable tension and compass signals in a wireless transmission mode, improves the safety and the reliability during the oil transportation process, is low in equipment cost and easy to install and operate, and does not require performing vocational training to related personnel.