The invention relates to a production method of hot rolled steel coil for shipbuilding. The method comprises the following steps of: (1) designing contents, preprocessing molten iron, then, smelting in a converter, switching nitrogen and argon and tapping to obtain molten iron; (2) continuously casting the molten iron to obtain a plate blank, controlling the molten iron amount to be 8-15t and theliquid level to be 200-350 mm when stopping casting a continuous casting tundish and wholly protecting and casting while the insertion depth of a long water opening is 300-400 mm; (3) heating the plate blank; and (4) finally, rolling and coiling the heated plate blank. The invention adopts a RPC (Relaxation-Precipitation-phase Control) and TMCP (Thermomechnical Control Process) rolling process, decreases the C and Mn contents by utilizing niobium microalloying treatment and decreases production cost. The D32-level hot rolled steel coil for shipbuilding has excellent plasticity and toughness, the extensibility is improved by over 8 percent, the welding performance of the material is improved and the favorable surface quality of a continuous casting blank is ensured.