Abstract: The present disclosure includes an ultrasound diagnostic apparatus with easy assembly and disassembly. The apparatus comprises an outer casing including a motherboard module having motherboard guiding plugs and motherboard ports installed thereon and a first outer-casing sliding device; and a main case structure being housed by the outer casing, including a transducer panel module coupled to an I/O module, a carrier board module coupled to the transducer panel module via the I/O module and having a PC module installed thereon process ultrasound data, carrier-board guiding holes to receive the motherboard guiding plugs, carrier-board ports to inter-plug in the motherboard ports, and a first main-case sliding device to slide in the first outer-casing sliding device and facilitate the main case structure to move relative to the outer casing; wherein the motherboard module and the I/O module are perpendicular to the transducer panel module and the carrier board module.