With the development of wireless communication, the cell density, spectral efficiency and communication quality have increased. Nevertheless, the users of a cell edge suffer a lot from co-frequency interference by adjacent cells due to high frequency reuse rate. A channel estimation method is proposed under Long Term Evolution(LTE) multi-cell systems. The proposed method can jointly estimate the Channel Frequency Response(CFR) of the serving cell and the strong interference cell, when both cells share the same pilot positions and there exist time offset and frequency offset. In the proposed method, a model is presented for the received signals with pilot positions, sequences, time and frequency offsets, then the Channel Time Response(CTR) is jointly estimated by solving the equations, and finally the estimated CFR is obtained by using the Fourier transform. The simulation results show that, compared with the conventional method, the proposed method can significantly improve the Bit Error Rate(BER) an d the Normalized Mean Square Error(NMSE) performance, especially when Signal to Interference plus Noise Ratio(SINR) is small.