Microstructure and mechanical properties of rheo-die casting YL112 aluminum were investigated with die casting semi-solid billets prepared by self-developed LSPSF（low shearing pouring sloping forming） on DCC280 horizontal die casting machine. The results indicate that the die castings with desirable mechanical properties and little defects can be produced with rotating speed at 90 r/min and tilting angular of 25°as well as preheating at 550 ℃ for mould and pouring at 620 ℃. Furthermore, the mechanical properties of the die castings can be improved after heat treatment.