The detection performance of resonant force sensor depends on the geometry dimensions, structure configuration and sensing mechanism of the resonant sensitive element. At present, the method of improving the detection performance by simply reducing the size has been in the bottleneck period. In order to study and develop a novel resonant force sensor, coordinate the contradiction between nonlinear vibration and resonant structure detection performance, explore a more sensitive sensing mechanism and improve its detection performance, a piezoelectric driven resonant magnetically coupled cantilever force sensor is proposed. Firstly, the design and theoretical modeling of the structure of the magnetically coupled cantilever beam are carried out. The influence of the external pressure on the vibration characteristics of the magnetically coupled cantilever beam structure is analyzed theoretically. With the increase of the pressure, the distance between the magnetically coupled cantilever beams decreases and the resonance frequency increases. Secondly, the experiment verifies the advantages of the bifurcation jump dynamic behavior, which increases the maximum amplitude by 2.8 times compared with the resonance of a single resonant beam. Then, two pressure detection schemes based on the bifurcation jump characteristics and frequency doubling response are studied, and the pressure detection is realized by using the critical frequency of the bifurcation jump and the high order response frequency when the mode is coupled. The sensitivity and linearity are analyzed. The experimental results show that the amplitude change of the detection scheme based on the bifurcation jump characteristic is obvious, which is about 5 times that of the detection scheme based on the frequency doubling characteristic, and it is easy to detect and overcome the adverse effects of nonlinear factors. The detection scheme based on frequency doubling response has high output sensitivity, which is about 4 times that of the detection scheme based on bifurcation jump, and large signal-to-noise ratio, which provides a certain reference value for designing resonant force sensors with different detection principles.