Abstract: In the Zeeman effect experiment，the diameter of the spectral line ring varies with the strength of

the magnetic field. This phenomenon can be used to measure the magnetic field. In this paper，the magnetic field

measurement formula is deduced，the law of magnetic field measurement error is found through practical measurement，

and the error propagation model is designed to simulate and demonstrate this rule，and the conclusions obtained

can guide the method of magnetic field measurement and improve the precision of measurement.

Key words: Zeeman effect, magnetic field measurement, error transfer, simulation calculation