Efficient nitrogen charging device

The utility model provides an efficient nitrogen charging device. The efficient nitrogen charging device comprises a cylinder barrel; the piston is arranged in the cylinder barrel and divides an inner cavity of the cylinder barrel into two oil cavities; the oil pump sequentially charges oil to two sides of the piston and drives the piston to reciprocate; when the piston moves once, nitrogen in the nitrogen cylinder is pumped into one side of the cylinder barrel, and meanwhile nitrogen on the other side of the cylinder barrel is pressed into the energy accumulator. When the piston directionally moves once, nitrogen in the nitrogen cylinder can be pumped into one side in the cylinder barrel, and meanwhile nitrogen on the other side in the cylinder barrel is pressed into the energy accumulator; when the piston reversely moves once, the nitrogen in the nitrogen cylinder can be pumped into the other side in the cylinder barrel, and meanwhile, the nitrogen on one side in the cylinder barrel is pressed into the ener