Abstract: Magnetic induction intensity of magnetic field is measured by using si-resistance-strain sensor and Ampere＇s law.The measurement principle is introduced and used it to measure the magnetic field of permanent magnets.The experimental results show that the present method has some advantages,such as the error is small,easy operate as well as an important reference value for open experimental teaching.

Key words: magnetic induction intensity, force sensor, Ampere＇s law