Construction method for improving embankment filler weak expansive soil lime

The invention discloses a construction method for improving embankment filler weak expansive soil lime. The construction method comprises the following steps: 1, testing the proportion of lime-improved weak expansive soil; 2, checking parameters such as longitudinal fracture elevation of a lower bearing layer to meet construction conditions; 3, performing quick lime digestion; 4, transporting the weak expansive soil to a construction site, and after filling of the weak expansive soil is completed, adopting a bulldozer for rough levelling and elevation measurement; 5, performing ash spreading by using a traction type full-automatic ash spreading truck, and controlling the spreading quantity of the lime by using a numerical control high-precision flow regulating valve; 6, actually measuring the water content of the filler, and adjusting the actually measured water content to be 1-2% higher than the optimal water content; 7, mixing by adopting a regenerator, wherein the mixing depth is controlled by adopting a m