The invention discloses magnesium phosphate cement recycled aggregate structure concrete and a preparation method thereof. The magnesium phosphate cement recycled aggregate structure concrete comprises the following components by weight percent: 12-30% of magnesium oxide, 8-20% of phosphate, 2-10% of composite retarder, 5-15% of admixture, 5-20% of recycled fine aggregate, 5-30% of recycled coarse aggregate, 0-10% of natural fine aggregate, 0-15% of natural coarse aggregate, and the balance being water. High early strength, small shrinkage rate, strong adhesive property and good corrosion resistance of the concrete are ensured by the magnesium phosphate cement; stable growth of the strength of the concrete is ensured by the admixture, and the durability and the volume stability are improved. The magnesium phosphate cement recycled aggregate structure concrete has the beneficial effects that the concrete material is applicable to the structure concrete and high-performance recycled aggregate concrete, can be applied to civil engineering in bad environments such as sulphate attack, marine corrosion, high-temperature environment and low-temperature environment, efficient utilization of the waste concrete is achieved, mining of natural gravel is reduced, the construction cost is reduced, and the targets of recycling wastes and protecting environment are achieved.