The method to use high Si composition SiC particle reinforced Al Si alloy to make automotive engine piston by upsetting extrusion was proposed.The forging process mold of piston was designed.The influence on microstructure and mechanical properties of composition Particle Reinforced Al Si alloy by the technological parameters including forging speed，initial forging temperature，holding time of the billet on formability was studied．The results show that gradient distributed SiC particle reinforced Al Si alloy can be made by this method.The SiC particle distributing inside from piston skirt to ring groove zone was 3.7% to 13.6%.The formability of the Al 20%Si/SiCp alloy by spray forming was better with the initial forging temperature at 465 ℃，the forging rate was 0.05 s-1，and the holding time of the billet was 2 h.After solution and aging heat treatment on the piston，the tensile strength is reaching 382 MPa and the elongation of 6.0%.