A basic point in college physics teaching is to cultivate students' spatial imagination. Maxwell's rate

distribution law is a central content of the gas molecule kinetic theory，which is difficult for students to learn and

professors to teach during the teaching process of gas dynamics theory. Its formula is abstract，complicated and difficult

for students to understand. Based on the concept of velocity space， it is presented the surface area of the velocity

sphere is equivalent to the number of microscopic states of a single gas molecule，and the Langerian function is used

to derive the velocity distribution function of gas molecules in the ideal gas equilibrium state. This method is relatively

simple and easy for students to understand is helpful to cultivate their spatial imagination.