The invention discloses a multi-functional hammer which comprises a long arm, a hammer, a nail pulling head, a screw driver and a serrated knife, wherein the long arm comprises a first long arm, a second long arm and a third long arm; one end of the first long arm is connected with the hammer; the top of the hammer is connected with the nail pulling head; the other end of the first long arm is in threaded connection with the second long arm; a rivet hole is formed in an inner cavity of the second long arm; the rivet hole is connected with the screw driver and the serrated knife; the other end of the second long arm is in threaded connection with the third long arm; and the other end of the third long arm is connected with a wrench head. According to the multi-functional hammer, the long arm can be disassembled through rotation, and the disassembly and assembly are facilitated; the long arm is divided into the first long arm, the second long arm and the third long arm, and the screw driver and the serrated knife are mounted in the inner cavity of the second long arm, so that the polishing and cutting are facilitated; and the hammer and the nail pulling head are arranged at one end of the first long arm, so that the tools are integrated, the carrying is convenient, and the placing position does not occupy space.