This paper deals with the low-gain output feedback cooperative control for discrete-time linear multi-agent systems subject to actuator saturation. Based on the algebraic Riccati equations, semi-global exponential consensus is demonstrated for multi-agent system networks with a switching topology that is known or unknown to the agents. The combinational measurements are utilized to design the state observer. The estimated combinational states are used for controller design and Lyapunov stability analysis. The theoretical results are illustrated by a numerical example.