The invention aims to provide an electrostatic spraying device for the surface of a liquid accumulator. Two left installation pipes and two right installation pipes are installed for clamping the liquid accumulator, and then a rotary pillar arranged on the left side of the left installation pipes is driven by a rotating motor to rotate. When the rotary pillar rotates, sliding blocks arranged on sliding rails which are close to the liquid accumulator slide through manual work, and electrostatic spraying guns are driven to slide and conduct spraying on the surface of the liquid accumulator, so that the spraying is conducted efficiently and rapidly, and the labor is saved. In addition, dust suction hoops, dust boxes and aspirating pipes are arranged for sucking dust in the spraying process of liquid storing pipes. The electrostatic spraying device is simple in structure, easy to operate, capable of simultaneously conducting spraying on the surfaces of two liquid accumulators efficiently and rapidly, and suitable for production.