The effect of pre-compression on the tension-compression asymmetry in a hot-rolled Mg-3Al-1Zn alloy was investigated by Electron backscattered diffraction (EBSD) and X-ray diffraction (XRD). The tensile and compressive tests of the pre-compressed materials reveal that the tension-compression asymmetry is greatly reduced via pre-compression, which results in the production of twins facilitating the grain size refinement. Yield strength and peak strength are obviously enhanced. The orientation of the grains and the intensity of the basal texture are effectively modified through the twins resulted from pre-compression. Additionally, {102}-{102} twins are found to be generated in the previously formed {102} twins. The existence of these twins modifies the deformation behavior of the materials during re-deformation, which is beneficial to the reduction of the tension-compression asymmetry.