In the construction of the mined tunnels with flat roofs and straight walls in Beijing, collapse and ground surface settlement may occur. In the paper, the technical difficulties in the design and construction of mined tunnels with flat roofs and straight walls are analyzed, the design method, construction principle and requirement for the mentioned tunnels are proposed, the sequential support, advance support, primary support, construction step conversion and special measures taken for the mentioned tunnels are summarized, and three typical construction sequences are proposed.