The invention discloses a method for improving accuracy of determination of water content of crude oil, and the method comprises the following steps: step B, a distillation solvent is added into a heating bottle and stirred; step C, the crude oil is put into a crude oil homogenization system; step A, the heating bottle, an exhaust pipe and a condenser are connected in sequence; step D, a condenser pipe is communicated with the exhaust pipe by a connecting pipe, and an electromagnetic valve is arranged on the connecting pipe; step E, a liquid level sensor is installed in the condenser; and step F, the electromagnetic valve and the liquid level sensor are respectively connected with a controller. The crude oil is first homogenized, the evenly-mixed crude oil can effectively avoid bumping accidents in the heating distillation process; in the distillation process, the controller adjusts the working state of the electromagnetic valve to distribute oil and gas distilled in the heating bottle to the connecting pipe and the condenser pipe so as to avoid products obtained by the distillation to rush out the condenser and avoid bumping and sample rushing, and sample integrity and the accuracy of the determination of the water content of the crude oil can be ensured.