This invention is a ceramic grain reinforcing Al-base compound material and its preparation method, and relates to a Al-base alloy. Its components are: 2.5-15% TiN, 2.4-10%AIN, 4-6.5%Si, 0.5-1.5%Cu, 0.3-0.5%Mg, 0-0.8%Ni, 0-0.5%Ti, and the rest is Al, and the percentages are weight percentages; the preparation method adopts melt blending founding method, and the technique flow is: material matching-melting base body-adding reinforcing grains-melting-modifying treatment-pouring-heat treatment, and the size reinforcing grains is in the range of 5-10 mum, and the vacuum degree of the vacuum furnace is 1.3-1.6X10 to the power -3 Pa, the temperature is 670-800deg.C, the modifying agent is 1-18g / Kg compound material containing 1-6% Na nanometer Al alloy powder; the Al-base compound material of this invention has light weight, high modulus number, high intension, good heat-fast and wearable performances, and the preparation cost is low, the technique is simple and it can be industrially produced.