Disclosed in the application is a handheld three-dimensional ultrasound imaging system and method, comprising a handheld ultrasound probe, used for scanning and obtaining an ultrasound image; a display, control and processing terminal, connected to the handheld ultrasound probe wiredly or wirelessly. The handheld ultrasound imaging system and method of the application further comprises: a handheld three-dimensional spatial positioning system, connected to the handheld ultrasound probe, moving with the movement of the handheld ultrasound probe, connected to the display, control and processing terminal wiredly or wirelessly, and used for independently positioning the three-dimensional position of the handheld ultrasound probe. By means of the handheld three-dimensional ultrasound imaging system and method of the present application, the large spatial positioning system in an existing three-dimensional ultrasound imaging system is changed into a portable spatial positioning system that can be used at any time, so that handheld three-dimensional ultrasound imaging can be widely applied.