Abstract: The nonlinear characteristics of rock mass become increasingly prominent with the increase of depth,and its mechanical parameters can be accurately measured and monitored in real-time,which provides a necessary basis for rock mass change characteristics and stress monitoring in the process of in-situ stress relief. At present,however,rock mechanics parameter measurement is mostly based on laboratory mechanics test. Timeliness and fitting method will bring errors to test results. Conventional coupled ultrasonic transmitting and receiving probes have high requirements for the flatness of the contact surface,so it is impossible to achieve long-term monitoring in the field borehole. Based on the dry-coupled point-contact acoustic probe velocity measurement technology,through the design of acoustic emission and reception probes,the stability of the circuit board and the research of denoising algorithm,a digital wave velocity acquisition system with instantaneous acquisition and wireless transmission functions has been developed. Based on the same area taken from the scene processing ϕ50 mm×100 mm granite rock and ground stress relieve core,the laboratory mechanics test and the determination of wave velocity were conducted,respectively,to obtain corresponding static and dynamic modulus of elasticity. The results show that firstly, the self-developed acoustic velocity acquisition system based on dry coupling point-contact has a good adaptability to different working contact surfaces,and the data error is within the allowable range of the specification. Secondly,for rock samples with the same lithology and different scales and forms in the same region,the dynamic and static elastic modulus relationship is applicable to each other. This pro- vides a basis for calculating the dynamic elastic modulus of rock mass based on dry coupling point-contact acoustic ve- locity measurement and calculating its static elastic modulus. Furthermore,based on the digital acquisition system of dry-coupled point-contact acoustic velocity measurement,it is feasible to collect and analyze the dynamic and static mechanical parameters of rock mass in real time during the process of in-situ stress core relief and long-term monito- ring of rock mass.