The invention discloses a settling basin capable of automatically regulating liquid level height and flow rate. The settling basin capable of automatically regulating the liquid level height and the flow rate comprises one or multiple settling small basins which are successively connected, wherein a water inlet pipe is arranged on the left side of the settling small basin at the leftmost end, thefront end of the water inlet pipe is bent, a water inlet of the water inlet pipe is arranged to be adhered to the wall, the highest point of a communicating pipe is lower than that of a grease discharge outlet of the settling small basin which corresponds to the communicating pipe, when the liquid level height of the settling small basin reaches the discharge liquid level of the communicating pipe, the flow rate of the communicating pipe is automatically regulated according to different liquid level heights of the settling small basin to regulate the liquid level height of the settling small basin, and settled sewage is discharged or discharged into the lower-stage settling small basin till the last-stage settling small basin and finally discharged. The settling basin is compact and beautiful in structure and high in space utilization ratio, can select different communicating pipe structures in a targeted state to change the capacity of the settling basin on regulating the liquid levelheight and the flow rate, and further is thorough in sewage separation effect.