The invention relates to the technical field of flight vehicles, in particular to a tethered balloon with an external separated type pneumatic structure. The tethered balloon comprises a balloon body, a windproof cover, one upper tail wing, two lower tail wings and a communication pipe, wherein a first membrane is arranged in the balloon body; the inner part of the balloon body is divided into a main air bag arranged at the upper part and an auxiliary air bag arranged at the lower part by the first membrane; the number of the upper tail wing is one and the number of the lower wing is two, the upper tail wing and the lower tail wings are arranged at the tail end of the balloon body to form a reversed Y-shaped structure; the upper tail wing is communicated with the main air bag; the windproof cover is arranged under the auxiliary air bag and is connected with the balloon body; the communication pipe is arranged at the outer part of the balloon body; the two lower tail wings are both communicated with the auxiliary air bag through the communication pipe. According to the tethered balloon disclosed by the invention, a separated type structure is adopted between the communication pipe and the balloon body, and the communication pipe is not welded with the balloon body, so that the problem of stress concentration generated by the balloon body of a connecting area due to the same pressure of the communication pipe and the ball body is avoided, and the risk of the balloon body is effectively reduced.