Pressure sensor and pressure sensing circuit thereof

A pressure sensing circuit is electrically connected with a coil, and the coil is positioned in a magnetic force range of a magnetic piece. The pressure value pressure sensing circuit includes a displacement sensing circuit and a conversion circuit, wherein the displacement sensing circuit is electrically connected with the coil and used for receiving induction electromotive force, calculating displacement of the magnetic piece according to an induction electromotive force value and outputting the displacement when the magnetic force is pushed by pressure of a pressure source to enable the coil to generate the induction electromotive force; and the conversion circuit is electrically connected with the displacement sensing circuit and used for converting the displacement of the displacement sensing circuit to a voltage signal corresponding to the displacement and outputting the voltage signal. In addition, the invention further provides a pressure sensor with the pressure sensing circuit and a structure of the