The invention is a movable surface runoff observation device, which is applicable to the observation of surface runoff under various field conditions. This device is mainly composed of five parts: runoff collection device, runoff sample collection device, runoff measurement device, data measurement system, and rain protection cover. The device can be used to directly measure surface runoff under various areas, different land use modes, different management measures, different slopes, and slope lengths. Compared with the traditional runoff plot observation, it is mobile, directly observes the runoff under natural site conditions, has high sample collection accuracy, low cost, high utilization rate, wide application range, and can observe the runoff intensity per unit time, etc. Advantages: Compared with the existing mobile runoff observation device, it has the advantages of being able to meet the large flow of runoff observation in the field, easy installation and operation, electronic records, high observation accuracy, and less failures. The device is easy to install and use, the result is real, the cost is low, and it is suitable for popularization.