The invention discloses a multifunctional operation marking pen. The multifunctional operation marking pen comprises a pen rod with an ink storage function, a piston device which is installed in the pen rod and has an ink suction function, a pen refill which is arranged at the end part of the pen rod and used for marking, and a pen cap which is sleeved on the pen rod. The multifunctional operation marking pen is characterized in that: the pen cap is composed of a shell, a pen hanger and a banding ring which is installed between the shell and the pen hanger and can rotate around the axial line of the shell; the pen hanger is hinged with the banding ring; multiple graduation marks are peripherally distributed on the external circumference of the banding ring; marking lines which are matched with the graduation marks and used for measuring the angles are arranged on the shell; and multiple through holes for the passing of the pen refill and the graduation marks used for measuring the length are arranged on the pen hanger along the length direction. The multifunctional operation marking pen has the advantages of simple structure and low cost, and is convenient and safe for use.