The invention discloses dual-beam laser selective melting and moulding equipment with an exchangeable powder cylinder. The equipment comprises two optical systems, a frame, a workbench plate, a powder feeding cylinder, a powder storage cylinder, a moulding cylinder, a powder returning cylinder, a moulding cavity, and two first driving mechanisms, which are used to respectively drive the moulding cylinder and powder feeding cylinder to move up and down. The workbench plate is fixed on the frame, the moulding cavity is fixed on the upper surface of the workbench plate, and the powder returning cylinder, the moulding cylinder, the powder feeding cylinder, and powder storage cylinder are fixed on the lower surface of the workbench plate from left to right in sequence. A scraper is arranged in the moulding cavity, and a second driving mechanism is arranged on the frame. A substrate is arranged in the powder feeding cylinder, a substrate is arranged in the moulding cylinder, the lower ends of the powder feeding cylinder and the moulding cylinder are both provided with a cylinder end cover, and the substrates are connected to a first piston system. A second piston system is arranged in the powder storage cylinder. The provided equipment has a high moulding efficiency and is capable of effectively reducing the deformation and cracking of members.