Abstract: In order to optimize the technology parameters of construction waste paste filling materials, taking construction waste as aggregate, coarse fly ash as cementing material, orthogonal test method is used to analyze the influence of slurry mass concentration, the proportion of cementing agent and recycled aggregates on slump, layering degree, exudation rate and uniaxial compressive strength of material filling body. The results show that the proportion of cementing agent and recycled aggregates has important effect on paste slump and exudation rate; paste concentration and the proportion of cementing agent and recycled aggregates are main influence factors of layering degree, filling body compressive strength; the greater the proportion of cementing agent and recycled aggregates, the greater the paste slump, the greater the exudation rate; the greater the paste concentration, the small the layering degree. The influence of fine aggregate proportion on paste slump, layering degree and exudation rate is not obvious. By comprehensive consideration, the optimal proportion way is choosing the proportion of cementing agent and recycled aggregates of 1:2, mass concentration of 76%, and fine aggregate proportion of 45% finally.