It is very important to research and master the rule of incremental forming of magnesium alloys carried on ultrasonic vibration under different process parameters for theoretical and practical application.This has significant value of theory and engineering application to solve the deficiencies,such as plate uneven heating and heating slower,along with the changing temperature of the lubricant film caused adhesion in partial higher temperature,along with the rising temperature of the mold strength and service life gradually reduce ect,and to improve the progress of the magnesium alloy plate ultrasonic vibration single point incremental forming.Take square pyramid box for research and the maximum shear stress,reduction ratio,forming accuracy as index to analysis the performance impact of different parameters to the magnesium alloy plate ultrasonic vibration single point incremental forming,such as the tool head size.the thickness and the amplitude. The result show that not only the maximum shear stress and the maximum reduction have been reduced but also the forming accuracy has been improved obviously after applying ultrasonic vibration.Also found that when the tool head diameter is 10mm,thickness from 1.0-1.3mm the amplitude is 0.04mm,it can improve the forming properties obviously.