Under the framework of crystal plasticity theory, a cyclic constitutive model based on dislocation density for face-centered cubic metals is proposed. The total dislocations are discretized into edge and screw components, and the multiplication, annihilation and interaction of dislocations are considered as the basic evolutionary mechanisms. At the same time, a cyclic constitutive model of single crystal is established by using the modified non-linear kinematic hardening rule. Then, the model is extended from single crystal scale to polycrystalline scale by explicit scale transition rule. The ratchetting strain of polycrystalline copper with typical face-centered cubic structure is simulated by using the proposed model. The numerical results show that the model can not only simulate the ratchetting strain and cyclic hardening characteristics of materials at polycrystalline scale, but also predict the ratchetting of materials at different orientations and stress levels from single crystal scale.