High energy cosmic ray electrons and positrons provide us a unique probe of Galactic high energy processes and a window for new physics, in particular the annihilation or decay of dark matter particles. Thanks to the development of large area and high resolution particle detectors in space, we can now measure cosmic ray electrons and positrons to energies well beyond TeV with very high energy resolution and low background, which shed new light on the search for dark matter particles. The Chinese Dark Matter Particle Explorer (DAMPE), launched in the end of 2015, is dedicated to such kind of observations. After nearly two years operation in orbit, the DAMPE has published the first results about the high precision measurement of the electron plus positron fluxes up to 5 TeV. In this talk the background of cosmic rays, the observation and data analysis of DAMPE, and the physical implication of the results will be presented.