The invention relates to the technical field of oil-gas exploration and development, in particular to a filling, sand prevention and steam injection integrated device, and further, an operating methodfor conducting operating by using the filling, sand prevention and steam injection integrated device. The filling, sand prevention and steam injection integrated device provided by the invention comprises a filling inner pipe, a filling outer pipe, a first sealing unit and a second sealing unit. Through the integrated design of the filling, sand prevention and steam injection device, filling, sand prevention and steam injection operation can be conducted through a set of pipe strings, the process program is simplified, the construction period is shortened, the operating cost is lowered, and complex situations are also avoided; and secondly, through cooperative arrangement of the first sealing unit and the second sealing unit, the problem of shaft sealing in the processes of filling, sandprevention and multi-cycle steam injection is effectively solved, it is ensured that sealing can be kept for a long term in the processes of filling, sand prevention and multi-cycle steam huff and puff, and the lasting and efficient sealing property is achieved.