The invention relates to the technical field of the detection of a pile foundation, and particularly relates to a pile foundation quality detection device of shock excitation in a pile side prospect hole. The pile foundation quality detection device comprises an acceleration sensor and a guide pipe, wherein the acceleration sensor is arranged on the side wall of the top of the pile foundation, the guide pipe is arranged in peripheral soil at the side of the pile foundation and is parallel to the pile foundation, the bottom end of the guide pipe is closed, the top end of the guide pipe is open, a shock excitation source capable of moving up and down is arranged in the guide pipe, the acceleration sensor receives a pile body response signal when the shock excitation source excites the vibration on various positions in the guide pipe, a processing unit acquires position information of the shock excitation source and output information of the acceleration sensor and processing the information to obtain the pile foundation quality information; in addition, the invention also relates to a detection method of the device. A drill hole is arranged by the side of the pile foundation, the shock excitation source is arranged in the drill hole, the pile body response signal is received by the acceleration sensor arranged by the side of the pile body, the position of the drill hole and the acceleration sensor is not subjected to the limitation of the pile top structure, and the pile foundation under construction or the pile foundation on active service can be detected.