Steel plate-masonry composite(SPMC) construction is a new method for the renovation of existing masonry walled buildings. To understand the shear behavior of the SPMC beam, six composite specimens were tested. The tests took into account the influence of the bolt spacing and the thickness of the steel plate. The shear failure mechanism was also examined.The test results show that the steel-plate and masonry collaborated well, and the damage sequence of both was not obvious. The damage of the composite beams always initiated from the local buckling of the steel plate in the shear-span section. The increase of the thickness of the steel plate significantly improved the critical buckling stress of steel plate and the ductility of the composite beams. Moreover, rather than the bolt-spacing, position arrangement of the bolts in the shear-span section remarkably affected the bearing capacity. Eventually, a design equation was given to calculate the shear capacity of such composite beams.