The invention relates to a film double-side microstructure reel-to-reel UV curing molding device based on a strap-shaped mold. The device comprises an unreeling module, a UV curing module, a protective film sticking module and a reeling module, which are erected on a frame and connected in sequence, wherein the unreeling module is connected with the UV curing module through an adjusting component; the UV curing module comprises a forward-direction UV curing module and a negative-direction UV curing module; the protective film sticking module is used for sticking a protective film onto the surface of a UV cured film substrate; finally the film substrate is reeled by the reeling module finally. The device adopts a double-side one-step curing molding technology and combines forward-direction UV curing and negative-direction UV curing technologies to realize the process of double-side microstructure molding curing based on one-off unreeling and reeling; meanwhile, a forward-direction UV curing mechanism adopts the strap-shaped mold, so that the mold filling time and the shape maintaining time are prolonged, and the mold filling effect and the microstructure molding result are improved.