The invention discloses a construction method of a high formwork with an arc-shaped structure. The construction method comprises the following steps that A, a formwork with an arc-shaped structure ismade, wherein the formwork comprises side formworks and a bottom formwork, the side formworks and the bottom formwork are equally divided into standard modules and non-standard modules, and each standard module and each non-standard module are numbered; B, data analysis and setting-out positioning are performed according to measuring datum points and a design drawing; C, formwork frames of a highformwork are arranged according to a setting-out result, vertical rods of the formwork frame are arranged along the positions of beam columns to be cast, the separating distances of the vertical rodsare adjusted towards slabs to be cast, transverse rods are arranged to connect the vertical rods to form a whole, a supporting system is formed, the formwork blocks corresponding to numbers are installed and reinforced at the positions of the beam columns to be cast according to the design; D, concrete is poured, curing and formation are performed, and the formwork is removed. By applying the method, the vertical rod adjustment difficulty is reduced, the use number of the formwork frames is decreased, the installing process is simplified, the construction progress is accelerated, the construction cost is greatly reduced, part of obliquely-crossed transverse rods are directly and vertically supported on the formwork, and a support stabilization effect is good.