Construction method of prefabricated inspection well

The invention relates to the field of inspection well construction, and discloses a construction method of a prefabricated inspection well, which comprises the following steps of: 1, preparing before construction; 2, positioning the rotary drilling rig; 3, ensuring that the cylinder wall is perpendicular to the horizontal plane, stabilizing the hole opening soil and protecting the hole wall from collapsing, and then burying a steel casing; fourthly, drilling construction is conducted through the rotary drilling rig; 5, checking the soil sample taken out by the drilling machine, and carrying out inspection well foundation construction after determining that the design requirement is met; sixthly, a well chamber of the inspection well is hoisted, and gaps on the outer side of the well chamber are backfilled with medium-coarse sand; seventhly, pipeline construction is conducted through a horizontal directional drill; 8, after directional drilling construction is completed, slurry in the well chamber is cleaned,