The invention relates to the technical field of hydrogeological detection, and discloses an
ultrasonic guided wave underground
water level detection device which comprises an ultrasonic probe shell, a
radio frequency assembly is arranged in the ultrasonic probe shell, and a probe rod
assembly is arranged at the bottom of the ultrasonic probe shell. The probe rod
assembly comprises a
longitudinal wave coupling solid rod, a hollow connecting rod, a
guided wave propagation hollow rod and a blade foot, the
radio frequency assembly comprises an inner layer sleeve, a plurality of wire bundles are arranged in the inner layer sleeve, and the bottom of each wire bundle is fixedly connected with a
phased array infinitesimal element. Ultrasonic longitudinal
waves are transmitted through a
phased array infinitesimal in an ultrasonic probe shell, so that the longitudinal
waves repeatedly interfere in a
longitudinal wave coupling solid rod to form cylindrical guided
waves propagating along the inner wall of a
guided wave propagation hollow rod, the cylindrical guided waves propagate to the deep part of a stratum and are reflected by underground water, and the infinitesimal receives and analyzes the
propagation time of the
reflected waves to calculate the
water level depth. The problem that traditional drilling measurement and an electromagnetic method are low in detection efficiency is solved, and the
water level detection accuracy and efficiency are improved.