Small rotary drilling rigs can generally drill 0.6- 1.2 m, and can also be equipped with reamers, and the bottom can be expanded to 1.4 m at most. Generally, the drilling depth of small rotary drilling rig is below 50m, and the diameter is within 1m8. The drilling depth of small rotary drilling rig produced by Shandong Rotary Force is generally between 10-30m, and the diameter of pile mouth is within 1m2. Because it is a pressurized drilling method, drilling can be carried out in general soil layers, and the drilling depth can be 20m, 1 hour.