According to some problems existed in current Chinese codes for design of seismic shear strength of concrete hollow block masonry, the curve of shear strength of concrete hollow block masonry under shear-compression loading, including descent segment, was presented by theory of failure region and test results of 58 concrete block masonry walls under shear-compression loading. And the design seismic shear strength formula of concrete hollow block masonry, which has reliability guarantee, was deduced. Compared with current Chinese codes, the design seismic shear strength formula of concrete hollow block masonry not only can perfectly simulate the shear-friction, shear-compression and diagonal compression failure modes, but also avoid unreasonable and unsafe calculation of seismic shear strength of concrete hollow block masonry, which can be applied to design of tall reinforced concrete masonry structures.