Refill friction stir spot welding test was carried out on 2219+5A06 aluminum alloy. The effect of technological parameters such as the rotation speed of the stirring head， the downward pressure-withdrawal speed and the indentation amount on the mechanical properties of the spot welded joint was studied. Shear tensile resistance test was carried out on spot welded joints with different parameters. The results show that the rotation speed of the stirring head and the downward pressure-withdrawal speed have a greater impact on the mechanical properties of the spot welded joint， the indentation amount has little effect on the mechanical properties. The test analyzes the microstructure of the spot welded joint， and weld joints can be divided into three parts： NZ（nugget zone），VTMAZ（vertical thermomechanical affected zone） and HTMAZ（horizontal thermomechanical affected zone）. The NZ and VTMAZ are small equiaxed grains， The HTMAZ forms a joint surface parallel to the plate，the VTMAZ and the hook defect at the root of the solder joint is a weak area of the mechanical properties of the solder joint.