The invention relates to the field of cast-in-situ bored pile equipment, in particular to a cylindrical soil taking drill bit. The drill bit comprises a cylinder body, the bottom of the cylinder bodyis provided with a fixed plate and a rotating sheet, the fixed plate is provided with a soil inlet, the rotating sheet can rotate in the circumferential direction of the cylinder body so as to open and close the soil inlet, and the edge of the side, close to the soil inlet, of the rotating sheet is provided with an excavation blade extending obliquely downwards. After being fully filled, the cylinder body rotates reversely, due to the fact that the excavation blade is subjected to the effect of resistance of a lower soil body, the soil inlet is closed by the rotating sheet, thus exposure of the soil body is avoided when the cylinder body is lifted upwards, the drilling soil-taking efficiency is greatly improved, during next soil-taking rotary excavation, due to the fact that the excavationblade is subjected to the effect of the resistance, the rotating sheet is pushed naturally to open the soil inlet, and the whole soil-taking process is convenient to operate.