The invention discloses a detection device and method for a sediment thickness of a pile bottom of a concrete grouting pile. The method comprises the following steps: starting a core drilling machine, and synchronously collecting a vibration frequency and displacement data of a drill bit in real time; according to the above data, calculating harmonic components of the vibration frequency of the drill bit and the position of the drill bit; and according to the above harmonic components, calculating starting and ending time of a sudden change and starting and ending positions of the drill bit but and calculating a core taking sediment thickness of the core drilling machine. A vibration sensor and a displacement sensor are respectively arranged on a drilling rig, the data of the above sensors are calculated and processed by a processing circuit, and the sudden change case in data processing is analyzed, such that the sediment thickness of the pile bottom can be detected. The invention as the detection device and method for the sediment thickness of a pile bottom of a concrete grouting pile can be widely applied to the field of core drilling detection of the concrete grouting pile.