Constraint measure and construction process of pipe roofing

The invention discloses a constraint measure of a pipe curtain and a construction process of the constraint measure. The constraint measure and the construction process are particularly suitable for earth excavation above an existing subway. A pipe-roofing working well adopts an open excavation sequential construction process, and steel plates and steel bars (including connectors) are pre-embedded in the working well close to a side enclosure wall of a subway; the working well is of a top-wall-plate-free structure, an upper beam and a lower beam are arranged on the side, close to a subway, of the working well, and steel bars are arranged in the upper beam and the lower beam and connected with steel bar connectors embedded in the enclosure walls. Steel plates are embedded in the upper beam and the lower beam, and two steel plate piles are welded with pre-embedded steel plates in the enclosure wall of the working well to form supporting brackets which are welded on the steel pipe curtain; the upper beam, the lo