Based on the standard transfer matrix method, the coupling mechanism between wave vectors of different regions in double potential well has been investigated. From a new viewpoint, the physical mechanism and the characteristics of energy states splittings have been explained and analysed with straightforward representation.The results show that electrons easily pass through from potential well to another one when the barrier is narrow. The stronger coupled wave functions will induce the energy states splitting easier.

double potential well system; energy states splittings；wave vector coupling.