The invention relates to a production method for a 9Ni steel plate capable of resisting residual magnetism increase and saving production energy consumption. Billet is subjected to processes of a heating process, a rolling process, a cooling process after rolling and a thermal treatment process to obtain a product. The production method specifically comprises the following steps: rolling, whereinan II type controlled-rolling process is adopted, rolling is not controlled at a first stage, and rolling is performed at an austenite re-crystallization stage, a rolling temperature is set to be 930DEG C or higher at a second stage, and the thickness of the billet before rolling at a second stage is lower than a target thickness by 1.6 times; cooling after rolling, wherein water is directly introduced after rolling, the water inlet temperature of the steel billet is controlled to be 830 +/-20 DEG C, the water outlet temperature is the room temperature, and a plate-strip-shaped martensite structure is obtained; and thermal treatment, wherein a room-temperature steel plate is subjected to subcritical quenching and high-temperature tempering. The production method is compact in flow, is lower in energy consumption, utilizes rolling waste heat to perform DQ thermal treatment, simplifies an offline thermal treatment process, saves energy consumption, shortens the production period, and facilities controlling residual magnetism better; and moreover, the performances of the steel plate are free of obvious deterioration, so that raw material requirements of an ultralow-temperature pressure container with high strength can be completely met.