Ｒainbow and secondary rainbow are common natural phenomena in the sky after rain．Ｒainbows are formed after sunlight is refracted twice and reflected once in raindrops．The secondary rainbow is formed by two reflections and two refractions of sunlight in raindrops．Because secondary rainbow is reflected in raindrops more than rainbow once，the light intensity will weaken． Therefore，the brightness of secondary rainbow is much weaker than that of rainbow，so secondary rainbow is very rare．The rainbow phenomenon eproduced by the traditional rainbow demonstrator is not obvious，and it cannot display rainbow and secondary rainbow at the same time． It is inconvenient to make，and has high reproduction requirements． It cannot be studied quantitatively．After in-depth and detailed research，a new rainbow and secondary rainbow demonstration device is made to reproduce the rainbow and secondary rainbow phenomenon．The device has the advantages of simple operation，high portability，obvious phenomenon and low environmental requirements．It can also quantitatively study the influencing factors of rainbow and secondary rainbow．The demonstration of the rainbow and secondary

rainbow demonstrator can deepen the understanding of optical phenomena in the atmosphere and the principle

of rainbow and secondary rainbow formation．