Broaching construction method for constructing cast-in-situ bored pile through impact reverse circulation drilling machine

The invention discloses a reaming construction method for constructing a cast-in-situ bored pile through an impact reverse circulation drilling machine, and the reaming construction method aims at a pile hole with the diameter larger than 2.5 m, and comprises the following steps that according to the designed pile hole diameter, an initial impact hammer head is used for constructing the pile hole with the diameter smaller than the designed pile hole diameter, and then the pile hole with the diameter smaller than the designed pile hole diameter is constructed; the rock breaking sectional area of the pile hole is about 60% of the sectional area of the designed pile hole, and then a reaming impact hammer head is used for reaming construction to the designed pile diameter till the designed hole depth is achieved. The whole pile hole construction is decomposed into the construction of the initial pile hole and the reaming pile hole, under the condition that the weight of the rated lifting impact hammer head of the