Abstract: With the development of stone mining and cutting technology, the construction-used stone masonry blocks have been changing from traditional stone blocks to modern machine-cutting stone blocks. There exists a distinct difference of interfacial performance on the bed joint between these two kinds of stone masonry walls. Double shear test of fifteen machine-cutting stone walls was carried out to investigate the shear performance of the bed joint. The main test parameters are mortar strength, compressive stress level and interface processing methods. The stress characteristics, failure modes and shear strength of the bed joints were investigated base on the test result. Orthogonal test was also used to study the influence of different parameters to the shear performance of specimens. Test results indicated that the failure mode of the bed joint is brittle shear one. The maximum shear strength was reached once cracks along the bed joint appeared and slip was followed immediately. The interface processing methods shows the most influenced degree on the shear performance of specimens while the mortar strength shows the least. A calculation formula of shear strength for machine-cutting stone walls was proposed based on statistical analysis of the test results and the calculation results show a good agreement with the test data. This paper can be referenced for engineering practice of stone masonry structures.