The invention provides a high-strength high-
plasticity heat-resistant 
magnesium alloy component and a preparation method thereof, the high-strength high-
plasticity heat-resistant 
magnesium alloy component comprises the following components: 5.0-9.0% of Gd, 2.0-6.0% of Y, 0.1-0.5% of Zn, 0.3-1.0% of Zr, and the balance of Mg and inevitable impurities, and the sum of the 
mass percent of 
rare earth elements Gd and Y in the component composition is 8-12%; the preparation method comprises the steps of 
alloy smelting, homogenization treatment, strong plastic deformation, hot forming and warm deformation, specifically, an obtained formed part is heated at the temperature of 200-250 DEG C, heat preservation is conducted for 2 h, then the formed part is put into a mold preheated at the temperature of 200 DEG C, the deformation amount is controlled to be 3-10%, and heat treatment is conducted. The prepared 
magnesium alloy component is fine in grain, the tensile strength at the 
room temperature is larger than or equal to 428 MPa, the percentage elongation after fracture is larger than or equal to 12%, the tensile strength at the temperature of 200 DEG C is larger than or equal to 358 MPa, the percentage elongation after fracture is larger than or equal to 13%, the 
magnesium alloy component can widely replace 2A12 and other medium-strength aluminum alloys, and the application range of the 
magnesium alloy can be further expanded.