The invention provides an improved balancing container for a boiler and an operating method of the improved balancing container. The improved balancing container comprises a cylinder body. A liquid storage cavity is formed in the cylinder body. A partition is arranged in the liquid storage cavity and partitions the liquid storage cavity into an upper cavity body and a lower cavity body. A communicating pipe is arranged on the partition. An upper water inlet pipe is arranged on the upper portion of the cylinder body. A lower water inlet pipe is arranged on the lower portion of the cylinder body. The upper water inlet pipe communicates with the upper cavity body. The lower water inlet pipe communicates with the lower cavity body. A low-pressure drainage pipe is arranged on the side of the cylinder body and communicates with the upper cavity body. A first three-way valve is arranged on an outer pipe opening of the low-pressure drainage pipe. The other two valve openings of the first three-way valve are correspondingly connected with a drainage pipe and a low-pressure sensor. A high-pressure drainage pipe is arranged at the bottom of the cylinder body and communicates with the lower cavity body. A second three-way valve is arranged on an outer pipe opening of the high-pressure drainage pipe. The other two valve openings of the second three-way valve are correspondingly connected with a drainage pipe and a high-pressure sensor. A guide sliding face is arranged on the inner wall of the cylinder body. A sliding rim is arranged on the periphery of the partition. A drive mechanism is arranged on the outer portion of the cylinder body and connected with the partition.