Abstract: High-silicon Mg-9Al-6Si aluminum alloy prepared by conventional casting was homogenized, and then treated by one-pass forward extrusion and eight-pass reciprocating extrusion, respectively. The effects of different extrusion techniques on microstructure and compression property were investigated. The results show that forward extrusion had no obvious effect on fragmentation and refinement of the Mg2Si phase in the magnesium alloy, while reciprocating extrusion had obvious effect. Mg2Si phase refinement could improve the compression property of the alloy. The compression strength, compression yield strength and hardness of the alloy eight-pass reciprocating extrusion were 494.5 MPa, 344.1 MPa and 149.4 HV respectively, which were 465.4 MPa, 207.6 MPa and 130.7 HV. The compression failure of both the alloys was brittle fracture along the axial direction.