Abstract: Objective The purpose of the paper was to study microstructure and properties of 1050A pure aluminum/TA15 titanium alloy dissimilar metal cold welded joints. Methods Butt welding test of 1050A pure aluminum/TA15 titanium dissimilar metal was carried out by JH-2000 cold welding machine. By optimizing welding parameters, connection of aluminum/titanium dissimilar metal by cold welding technology was realized. Due to characteristics of high frequency discharge and instantaneous high temperature of cold welding, welding heat input was low, and IMC layers at the interface of welded joints were thin. The high quality joints with good forming quality and near-defect-free internal could be obtained by cold welding. Results The results showed that under welding parameters of pulse time 30 ms and pulse current 30A, IMC at the interface of welded joints was the least, and average tensile strength of welded joints was 120.3 MPa, which was more than 88 % that of aluminum base metal. The fracture type was ductile-brittle mixed fracture, and weld zone on the aluminum side of interface was weak zone of mechanical properties of dissimilar joints. Conclusion Combined with microstructure of welded joints, heat input had a great influence on formation and quantity of IMC layers at the interface of titanium/aluminum dissimilar joints. The number of IMC significantly affected mechanical properties of aluminum/titanium dissimilar metal welded joints.