The availability of high spatial resolutions rainfall runoff data is vitally important in water resource estimation and management. To settle the problem of untimely collection of rainfall runoff caused by the uncertainty of rainfall, an unattended rainfall runoff collector with remote control was developed. According to the whole system, when the trigger device detects rainfall runoff, an energy-saving circuit connects, and the sampler is powered. At the same time, state and position information are sent to the mobile phone through the communication module. Then, the mobile phone sends instructions and starts an order back to the sampler through texts based on different requirements. The instructions and start order are then passed to the single-chip micyoco (SCM) control system, which also occurs via the communication module. A disconnected signal will be sent to the energy-saving circuit after the rainfall runoff collection. This signal will power off the sampler at the end. Test experiments showed that the maximum sampling error of the sampler developed in this paper was 1′02″, and the minimum sampling error was 22″.