The invention discloses a tenon-and-mortise heart sound probe based on an MEMS (micro-electromechanical systems) sensor, belongs to the technical field of medical instruments and solves the technicalproblem that a heart sound probe is easily interfered by external environments as detected heart sound signals are weak. According to the tenon-and-mortise heart sound probe, a detection head, a connector, a probe base, a protective rubber ring, a negative-pressure bag connection fastener and a negative-pressure bag are sequentially connected through dovetails and dovetail grooves, the heart soundprobe is modularly decomposed by the design of a tenon-and-mortise structure and then micro-structurally integrated, the size of the probe is greatly reduced, craft production difficulty is reduced,the detection sensitivity of a bionic 'ciliary' sensor chip is enhanced, the influence of environmental noise on the chip is greatly reduced, and the signal-to-noise ratio of the chip is increased.