Abstract: Installing sensors inside the metal rollers to monitor the belt’s operational status represents a promising sensing approach, characterized by real-time data acquisition, high integration and minimal environmental impacts. However, through-metal-roller communication is a challenging task due to the limitations of conventional wired transmission and electromagnetic wave wireless transmission. This paper aims to develop a robust through-metal-roller communication system to facilitate efficient data transmission. Herein, an ultrasonic through-metal-roller communication system based on ultrasonic through-metal communication technology is proposed and its channel characteristics are investigated, aiming at realizing reliable through-metal-roller data transmission and communication. In this paper, the through-metal channel is first simulated and modeled as a cascade of primary path subsystem that generates the original received response signal and echo subsystem that generates the echo response. The through-metal channel is analyzed to study its channel characteristics, and the elimination method of the channel echo is studied. A practical ultrasonic through-metal-roller communication system according the design is constructed and its amplitude-frequency response is measured. Subsequently, it separates the primary and echo signals from experimental data and employ a nonlinear least squares estimation algorithm to determine the transfer function parameters. Experimental findings demonstrate good applicability in metal channel modeling methods and excellent agreement between estimated system transfer functions and the actual model. The proposed ultrasonic through-metal-roller communication system has high reliability and feasibility.