The invention relates to a 
voice coil-piezoelectric 
hybrid large displacement 
actuator. The 
voice coil-piezoelectric 
hybrid large displacement 
actuator is composed of a magnetizer, an annular permanent 
magnet, a hollow iron core, a pull rod, a coil, a locking end, a cover plate, a piezoelectric amplifying mechanism, a limiting block and a screw. A process of realizing large displacement actuation is as follows: a uniform air-gap 
magnetic field is produced between the magnetizer and the annular permanent 
magnet inlaid in the magnetizer, the coil is arranged in the 
magnetic field, one end of the coil is connected with the pull rod, the pull rod sheathes inside the hollow iron core, the hollow iron core clings the annular permanent 
magnet and is connected with the bottom of the magnetizer in a communicating manner; the magnetizer is fixed at the locking end; the piezoelectric amplifying mechanism is composed of a piezoelectric stack and a 
tertiary displacement amplifying mechanism and sheathes the fine end of the pull rod, and a third rhombohedral ring 
short axis tooth socket of the 
tertiary displacement amplifying mechanism is meshed and locked with a tooth socket in the inner wall of the locking end; the piezoelectric stack is electrified, the third rhombohedral ring 
short axis is shortened, and locking is relieved; then quantitative and directional current is applied to the coil, 
ampere force is produced, and the pull rod is pulled; and if the piezoelectric stack is 
cut off from 
electricity, locking is realized again, and large displacement and 
force output of position locking are realized.