Based on output increment feedback GPC and some algorithms to solve the problem of input constrains, a new output increment feedback GPC with input constraints is proposed. The operation of inverse matrix is avoided by approximately computing the future control increment sequence off line, so that the on-line computation burden is strongly reduced. Moreover, the algorithm can obtain the optimal control input by adjusting the set-value of max-output increment and guarantees that output close to the set-value. Simulation results show that the proposed algorithm is effective.