Abstract: Characteristic point and echo arrival time of the ultrasonic water meter based on the dual-threshold method are determined by the first and second threshold voltage detections. However, the characteristic point and arrival moment of the echo signals are susceptible to deviation from the actual values due to changes in the measurement environment, thereby decreasing the measurement accuracy of the ultrasonic water meter. To address this issue, an echo characteristic peak search method based on the dual-threshold method is proposed. The echo characteristic peak and arrival time are preset, and the echo arrival time is self-adjusted using the relationship between the speed of sound and temperature. The echo characteristic peak is searched by comparing the preset arrival time with the measured arrival time to accurately position the echo signal characteristic point. This reduces the effect of temperature variations on the arrival time and ensures accurate time-of-flight measurements. Flow test experiment results show that the prototype exhibits excellent metrological characteristics at temperatures of 10 ℃, 20 ℃, and 50 ℃. The maximum measurement errors of the prototype are less than 1.00% at high flow rates and less than 2.00% at low flow rates. Repeatability is better than 0.40% and 0.60%, respectively. The prototype meets the performance requirements for accuracy class 1 water meters, proving the method's validity.