The invention relates to a human-machine authority switching method based on steering wheel grip strength, which comprises the following steps in sequence: detecting driver grip strength through a pressure sensor; converting a resistance signal emitted from the pressure sensor into a voltage signal; reading the voltage signal and converting the voltage signal into a corresponding pressure value according to the characteristics of the pressure sensor; detecting ownership of the current vehicle control right; judging whether the signals emitted by the three pressure sensors reach the switching condition; judging whether the driver is out of the driving state and judging whether the steering wheel should be taken over by the auxiliary system; sending the determination result of the switchingstrategy to the auxiliary system controller. The invention also discloses a device for realizing human-machine authority switching method based on steering wheel grip. The invention can monitor the driver's state in real time through the change of the grip force exerted by the driver on the steering wheel, judge whether the driver is out of the driving state and whether the steering wheel is intended to be taken over. The strategy is reasonable, the hardware structure is simple, and the reliability and the safety of the system can be enhanced.