Abstract：Low-powered up-conversion is a technique that low-energy light (long-wavelength) was absorbed by sensitizer and then high-energy light (short-wavelength) was emitted by the acceptor in the binary system, based on the triplet-triple annihilation mechanism. In order to enhance low-powered upconversion efficiency, a series of cyclodextrins (CD) such as -, - and -CD were firstly used to envelope the acceptor (2-chloro-9,10-xylene anthracene, DTACl) in the presence of sensitizer 5,10,15,20-tetraphenylporphyrin palladium (PdTPP) or 5,10,15,20-tetraphenylporphyrin platinum (PtTPP), which the ternary systems were formed. The results showed that -CD with appropriate cavity radius can effectively improve the fluorescence quantum efficiency (f) of DTACl and that sensitizer (PdTPP) with longer triplet lifetime is in favor of triplet-triplet energy transfer (TTT. As a result, the upconversion efficiency for ternary system (PdTPP/DTACl/-CD) was enhanced. Under the excitation of 523 nm diode laser (60 mW/cm2), bright green-to-blue upconversion was observed with the efficiency (UC) as high as 12.82%. With the help of Pt/WO3 photo-catalyst, the conversion from coumarin to 7-hydroxycoumarin was successfully achieved under the irradiation of our green-to-blue upconversion, indicating that low-powered up-conversion possesses potential application in the aspect of photocatalytic synthesis by solar energy.