The combination of co-time co-frequency full-duplex (FD) and multiple-input multiple-output (MIMO) techniques has the potential to double the spectral efficiency of the MIMO systems, but more complicated interferences arise, which limits the application of FD technique. Based on the concept of the interference alignment (IA), this paper presents a scheme for the multi-cell FD-MIMO systems to solve the problem. This scheme is both suitable for the FD base FD user (FD-BS-FD-User) mode and FD base half duplex user (FD-BS-HD-User) mode. In the scheme, the many to one (MTO) linear IA algorithm is proposed to eliminate the inter-cell and intra-cell interference of uplink and downlink in the closed form. Then the objective function is constructed based on the residual interference between uplink users transmitting and downlink users receiving(I-UuT-DuR),and then transformed into the composite cost function with the aid of the auxiliary function,which is only related to the uplink precoding matrix. Finally, the composite cost function is optimized to obtain the precoder with the gradient descent method on the Grassmann manifold in an iterative manner. Numerical simulation results verify the applicability and effectiveness of the proposed scheme for multi-cell FD-MIMO systems.