A developed light wall composed of oriented structural straw board (OSSB) and tennon-and-mortise connection wood frame (TMCWF) was introduced. The wall build-up with the wall-modular, top plate and sill plate, the wood frame members of a modular are connected with tennon-and-mortise, and the panel is OSSB. The seismic behavior of the light wall modular composed of OSSB and TMCWF was tested under low-cyclic loading based on seven modular-wall specimens, which have various spaces of vertical frame members, panel type, panel thickness, space of nails and vertical loads. The performances of the specimens such as the failure models, hysteretic curves, shear capacity and ductility are obtained. Experimental results show that the final failure is induced chiefly by penetrating the panels for nails; the hysteretic curves are typically reversed S-shaped; the type of panel, the thickness of panel, the space of panel nails are the major factors to influence the shear strength of the modular-wall; the rigidity is big at the initial stage and then reduced sharply; the displacement ductility factors of the wall-modular calculated with specification method are low.