The ground state properties of the strong coupling bipolarons in a parabolic quantum dot are studied based on the Lee-Low-Pines-Huybrechts variational method. The law of the effective potential Veff of the strong coupling bipolarons changing with the strength of the electron-phonon coupling α, the relative distance between two electrons r, and the radiu of quantum dot R0 are derived. The results show that Veff consists of three parts: Coulomb potential Vcoul, confining potential Vconf and induced potential Ve-LO. Ve-LO is always less than zero, and the absolute value |Ve-LO| increases when the strength α, and increases when the relative distance r between the electrons and guantum dot's radius R0 decreace. The absolute value |Veff| increases with the strength α increasing and increases with the relative distance r decreasing. α and r are the main factors to influence the effective value. However, the quantum dot's radius R0 and the dielectric constant ratio η have little influence on the effective potential Veff.
