The invention provides a gangue light-weight aggregate concrete compound block and a manufacturing method thereof. The method comprises the following steps: using cement as cementing material and gangue as blending material, adding fragmental stone and perlite, pressing into a block skeleton with bores by a block forming machine, wherein the block bores are filled with gangue foam concrete grout prepared from the gangue. In the invention, Gangue, cement and water are used to carry out the hydration reaction so as to produce high-strength hydrates, such as hydrated calcium silicate gel, hydrated aluminates, trithio hydrated calcium sulfate, single-sulfur hydrated calcium aluminate, hydrated garnet and the like, so that the block has high strength. The gangue foam concrete in the block bores has the advantages of low volume weight and low heat conductivity coefficient, so that the block can effectively prevent heat transfer in a wall structure and has favorable thermal insulation effect. Therefore, the block overcomes the defects of high volume weight, low strength, low heat conductivity coefficient and the like existing in similar products in the market. Meanwhile, since the block utilizes large quantities of low-cost gangue, the product cost is lower than that of the similar products.