Mobile robots often encounter complex obstacles during their operation, not the least of which are stairs. Suitable mechanical structures and adequate control algorithms are both equally important in stair climbing. This paper proposes a novel design for a multi-active crawler robot (MACbot) capable of autonomous stair climbing. The MACbot has four track modules for extended mobility and a recovery arm that facilitates self-rescue capabilities. By adopting the proposed smart clutch mechanism, the MACbot can provide a variety of motions with a minimum number of motors. This paper presents a static analysis for the mechanical design and details the stability analysis for an autonomous stair climbing algorithm. A series of experiments show that the MACbot can autonomously climb stairs reasonably well.