Annular reinforcing method for thick sand layer pile foundation

The invention discloses an annular reinforcing method for a thick sand layer pile foundation. The annular reinforcing method for the thick sand layer pile foundation comprises the steps that when the pile foundation is filled through the annular reinforcing method for the thick sand layer pile foundation, punching and sampling are conducted on a supporting point of a preset pile foundation at the bridge erection position, the position of the preset pile foundation is determined at the bridge erection position according to geological survey data, a foundation pit and a base pit are excavated through a rotary drilling rig, a curing agent is sprayed into the foundation pit and the base pit through a stirring pile machine, cement is sprayed into a soil body and fully stirred, soft soil is hardened, and the foundation strength is improved; and an anchoring assembly and a base are inserted into the cured foundation pit and the cured base pit correspondingly, concrete is poured into the foundation pit and the base p