The invention relates to the field of crossing of building formwork design and construction, in particular to a design and construction method of side face formworks of thick and large concrete structures. The design and construction method of the side face formworks of the thick and large concrete structures comprises the following steps of first, determining a calculation model of a formwork system; second, determining the axial tension of split bolts; third, determining materials of stress components of the formwork system; fourth, checking calculation of the bearing capacity of the formwork; fifth, checking calculation of secondary square beam bearing capacity; sixth, checking calculation of main square beam bearing capacity; seventh, checking calculation of split bolt bearing capacity; eighth, rechecking calculation of tensile strength of structural steel bars; ninth, manufacturing formworks; tenth, manufacturing a main square beam; eleventh, making bolts and cushion plates of thebolts; twelfth, bolt connection; thirteenth, fixing the formworks in place; and fourteenth, pouring concrete. According to the design and construction method of the side face formworks of the thick and large concrete structures, not only is the amount of split bolts used in the formworks reduced greatly, but also the key technical problems that the construction difficulty is large and the construction period is long are solved, and the prestressed force of a structural steel bar is established by using concrete lateral pressure to counteract the partial shrinkage stress of mass concrete, andthus the purpose of restraining cracking of a mass concrete structure is realized.