The invention discloses an expansion locking mechanism of winding type hinge expandable arms. The expansion locking mechanism comprises a locking top rod, a guide rail, a plurality of expandable arms, limit columns, locking pieces and locking fasteners and is characterized in that the locking fasteners are integrated with the expandable arms, component rigidity is enhanced, and locking reliability is increased; the expandable arms are sequentially hinged, have large free rotation angles and wind in a storage cylinder; the locking top rod is fixed at the upper end of the storage cylinder, and the locking top rod moves vertically under the effect of a compression spring; when the hinge sections of the expandable arms approaches the locking top rod along the guide rail, the locking top rod extrudes the locking pieces to fasten the locking fasteners to complete expansion locking, and the limit columns are arranged in the guide rail. The expansion locking mechanism has the advantages that the expansion locking mechanism is stable in expansion process, simple in mechanism, large in storage ratio, high in reliability, and the like; the expansion locking mechanism is applicable to fields such as large expandable antennas, solar panel substrates, space telescope shading cover expansion mechanisms and space platforms and widely adaptive to expansion locking tasks.