Abstract: The effects of nitrogen content on microstructure, mechanical properties and corrosion resistance of CoCrFeMnNi high entropy alloy were studied by rolling deformation and recrystallization at 1150 ℃ for 1 h. The results show that under the present preparation conditions, nitrogen is in interstitial state in CoCrFeMnNi high entropy alloy, without second phase precipitates. With the increase of nitrogen content, the hardness and corrosion resistance of the alloy improve.When the nitrogen content is 0.3wt%, the comprehensive performance is best. The microhardness increases by about 20.45%,the corrosion current density reduces by about 70.27%, the immersion corrosion rate reduces by 61.54%, and the density of the etch pit obviously reduces.