Reza,

There are many methods:

https://en.wikipedia.org/wiki/Speed_of_light#Measurement

Fizeau's method is my favourite - for its simplicity.

Light, as an electromagnetic phenomenon, is described by Maxwell's equations. In these equations, μ0 is the magnetic permeability of free space, and ϵ0 is the electrical permittivity of free space. In the absence of any charges, one solution to these equations is a traveling plane wave with velocity

c=1/seq root μ0 ϵ0

Of course, this leaves the problem of measuring μ0 and ϵ0, but is a great demonstration of the fact that light is truly an electromagnetic phenomenon. As an added bonus, μ0 and ϵ0 can be measured in a variety of ways, without requiring very high time resolution.

Hello Reza Karimzadeh !

How to measure the speed of light at your university with a dinner budget

Although the idea of using a modulated laser signal to measure the speed of light is not new, most methods found in international literature are still expensive, as a result of either the instruments or the circuits used. In the present approach, we provide an alternative that requires equipment that most universities own for their undergraduate programs, plus some inexpensive circuitry, allowing the students of any undergraduate physics laboratory course to obtain an eight-point graph using relatively small distances (such as corridors), combining a low budget with an accurate result that is equally as good as those achieved by kits available on the market.

Reference:

Article How to measure the speed of light at your university with a ...