The invention provides a blade assembly for a mixing drum, the mixing drum and a concrete mixer. The blade assembly comprises a blade body and blocking parts, wherein the blade body comprises an easy-to-wear part; the blocking parts cover outer sides of the easy-to-wear part of the blade body, both the front surface and the back surface of the blade body are covered with the blocking parts, and the blocking parts adopt mesh structures for stopping gravel from impacting the blade body. The blocking parts adopt the mesh structures, so that when the gravel impacts the blade body, the mesh structures can stop the gravel, and the blade body is effectively prevented from being damaged. The blocking parts are arranged on both the front surface and the back surface of the blade body, so that regardless of the condition that the blade body rotates forwards or reversely, the surfaces of the blade body can be protected, the wear degree of the blade body is decreased, the service life of the blade body is prolonged, the operation reliability of the blade body is improved, and the maintenance frequency and the maintenance cost are reduced. Meanwhile, the mesh structures can also play a role in retaining concrete.