An organic electroluminescent device, a method for preparing an organic electroluminescent device, and a display panel are disclosed. The organic electroluminescent device comprises a conductive layer formed by transparent magnetic conductive particles which are mixed in the sealing layer and stacked on a surface of the first transparent electrode layer. The conductive layer increases the conductive performance while not increasing the thickness of the first transparent electrode layer, thereby avoiding decrease of the light transmittance caused by increase of the thickness of the first transparent electrode layer, and avoiding the problem of voltage drop due to poor conductivity of the first transparent electrode layer, so as to improve the display effect and use stability of the organic electroluminescent device.