Abstract: Overtopping is one of the major factors leading to embankment dam failure. In order to study dam performance and evolution before dam failure, a full-scale overtopping failure test on embankment dam with the maximum height of 9.7 m is carried out. The monitoring techniques for the test with various instruments are introduced, including water level gauges, thermometers, osmometers, piezometer tubes, distributed optical cables, moisture transducers, inclinometers, multi-parameter transducers, total station, level gauges, etc. The seepage, deformation, temperature data and variation characteristics of the dam are monitored from dam filling, initial impounding to dam failure. The monitoring data are analyzed, showing the reliability and validity of the osmometers, moisture transducers, inclinometers and multi-parameter transducers, and their monitoring techniques are verified. The moisture transducers are more sensitive than the osmometers during reservoir impounding. The dam body deflects from upstream to downstream with the increase of reservoir water. The observed maximum dam settlement is 5.21%, and the observed maximum dam inclination is 2.242°. The research results are valuable to the study on the evolution mechanism of dams and the early-warning indices of unexpected accidents.