Abstract: A concrete nonlinear system with degree two and the least dimension (=3) was firstly given, and it was shown that the system has a heterodimensional cycle with double orbit flips. Then, by using Silnikov coordinates and moving frame, the bifurcation of the cycle was studied under the perturbation of degree three. The method given here provides a useful reference for constructing homoclinic, heteroclinic and heterodimensional cycles with various other kinds of degeneracy.