In-hole double-measuring point low-strain integrity detecting device and method for foundation pile

The invention discloses an in-hole double-measuring point low-strain integrity detecting device and a method for a foundation pile. The device comprises acceleration sensors with fixing devices, pre-embedded pipes, a pulse hammer, leading wires with scales and a data acquisition treatment device. The sensors adopted by the device consist of the acceleration sensors and the fixing devices; and wheneach acceleration sensor arrives at a designated position, the position of the acceleration sensor in the corresponding pipe is fixed by utilizing the corresponding fixing device. When a concrete pile is poured, pipes are required to be pre-embedded into a steel reinforcement cage for hanging and placing the sensors. When detecting is performed, the two sensors are respectively hung and placed atthe specific depth in the pre-embedded pipes, and the top of the pile is knocked by utilizing the pulse hammer; analysis is performed according to the results of the two measuring points; and the purposes of measuring concret