With the continuous improvement of market requirements for gas meter technology and accuracy, ultrasonic measurement technology has been widely used, and the development of ultrasonic gas meter has gradually expanded from industry to civil field. Because the composition of domestic gas source is relatively complex and the installation environment is relatively bad, it affects the accuracy and stability of ultrasonic measurement and restricts the rapid development of ultrasonic technology. The as6040 ultrasonic metering chip of Ruigan and the external expansion amplification circuit are adopted to successfully solve the problem of serious ultrasonic attenuation and insufficient signal input in harsh environment, help customers quickly realize gas design and accelerate the mass production and listing of gas meters.