Evaporation is one of the three elements of the natural water balance and water surface evaporation is an important project of hydrologic monitoring.With the rapid development of science and technology,modernization has been widely used in hydrologic monitoring and the traditional manual methods of monitoring of water surface evaporation are gradually being replaced by automatic monitoring.However,it is not clearly defined about the standard for observations of Water Surface Evaporation Code（SL630-2013）and other related specifications on the evaporator surface height measurement accuracy of field testing method in automatic monitoring technology of water surface evaporation.In order to explore the precision test method of water surface automatic evaporation system,taking Gaosha hydrological station as an example,an experimental study was carried out by simulating evaporation of water surface with artificial water intake and a comparative analysis of evaporation data between artificial and automatic observation was made.The results show that the surface height measurement accuracy of field testing method is in accordance with the requirements.The testing and evaluation method can provide a reference for other similar surface height measurement accuracy of testing method in automatic monitoring technology of water surface evaporation as well as a scientific foundation for the revision of the observation of water surface evaporation specification of order.