Based on a coordinate transformation, the boundary potential of a quantum rods is changed from the ellipsoidal form into a spherical one. The properties of strong-coupling magnetopolaron in a quantum rods in a three-dimensional anisotropic harmonic potential are studied using the linear combination operator and the unitary transformation methods. The relations of the vibrational frequency and mean number of phonons of strong-coupling magnetopolaron in a quantum rods with the cyclotron frequency of a magnetic field, electron-phonon coupling strength, aspect ratio of the ellipsoid and transverse and longitudinal effective confinement length are derived. Numerical calculation results show that the vibrational frequency and mean number of phonons increase with increasing of electron-phonon coupling strength and cyclotron frequency of a magnetic field and increase rapidly with decreasing transverse and the longitudinal effective confinement length. The vibrational frequency and mean number of phonons are increasing functions of the aspect ratio of the ellipsoid when e′>1, whereas they are decreasing functions of one when e′<1. When e′=1, the vibrational frequency and mean number of phonons are the minimum values.