We perform the calculations in Sr7Ti9O14 (Sr/Ti=7/9=77.7％) and discuss the effects of Ti-rich on the ferroelectricity and ferromagnetism.And the bandstructure and DOS(density of state) calculation is perfored and a band gap of 2.82eV is yielded using the GGA+U method while the experiment gap is 3.3eV.We adopt the former value of U=5 eV and J=0.64 eV for Ti 3d orbitals.