To investigate the rolling wave characteristics of overland flow, this study calibrated the accuracy of the depth measurement system for shallow flow on slopes using acrylic sheets and optimized it as a dual-line laser water depth measurement system. Non-contact measurement methods were used to measure the water depth at the mature cross-section position of rolling waves in real time. This experiment designed a total of 5 measurement intervals, namely 0.04, 0.05, 0.10, 0.15, and 0.20 m. Three horizontal gradients were set for the slope, namely 3°, 9°, and 15°, and six horizontal gradients were set for the flow rate, namely 2, 4, 8, 12, 16, and 20 L/min. Each horizontal gradient was repeated for 5 experiments. The results indicated that the accuracy of the depth measurement system for shallow flow on slopes was confirmed to be 0.473 mm per grid, and the optimal spacing for the dual-line laser depth measurement system was 0.04 m. Both flow rate and slope significantly affected the wave speed, wave height, height difference, and frequency of rolling waves. The influence of flow rate (the effect size values were 0.655-0.963) was greater than that of slope (the effect size values were 0.232-0.874). The slope significantly affected the wavelength, while the flow rate did not significantly impact it. Wave speed increased with flow rate but the influence of flow rate on wave speed decreased with increasing slope. Under different slope conditions, wave height responded differently to flow rate. At a 3° slope, wave height initially increased and then decreased with increasing flow rate, whereas at higher slopes (9° and 15°), the wave height increased significantly under low flow conditions (2-8 L/min), with the increases of 3.74 and 4.63 mm, respectively. The difference in wave height between 3° and 9° slopes increased with flow rate, but the difference between 9° and 15° slopes decreased. The variation in height difference with slope was influenced by flow rate, showing a trend of initially increasing and then decreasing. Increased flow rates led to an increase in frequency, with the largest increase at a 15° slope, up to 2.37 Hz. The frequency differences between slopes decreased and then increased as flow rate increased, with a critical flow rate of 8 L/min. At a low slope (3°), wavelength fluctuated with flow rate, whereas at a high slope (15°), higher flow rates inhibited the development of wavelength. Under the high flow conditions (16-20 L/min), the wavelength differences between slopes were significant. This research provides a theoretical basis for improving the accuracy of slope overland flow measurements and further elucidating the dynamic characteristics of overland flow rolling waves.