In this work, the simultaneous effects of electric field and impurity on the non-extensive entropy of a GaAs/Ga0.5In0.5As double cone-like quantum dot that is grown on a GaAs wet layer are studied. The system is under an external electric field directed along the −x direction. First, we have solved the Schrödinger equation using the finite element method. Then, we have used the Tsallis formalism and calculated the entropy of the system for different temperatures, electric fields and impurity locations. It is found that the entropy decreases with increasing the electric field and temperature. Since the electric field directed along the −x direction, the entropy reduces when the impurity moves toward the left hand side.