The coastal protection forest is the most basic living resources in the coastal ecosystem. Due to the high underground water level, high soil salt content, low fertility, and deteriorated ecological environment in the coastal area, the selection of plant species is the key to speed up the construction of coastal protection forest system. To evaluate the salt tolerance of Bambusa oldhamii and provide plant species for coastal protection forest in the coastal area, we investigated reflectance spectra and chlorophyll fluorescence parameters in the leaves of 2 years B. oldhamii under sea salt stress by hydroponics using Unispec-SC spectrometer and non-modulated chlorophyll fluorometer, respectively. Results showed that when the sea salt concentration was under 1.2%, the contents of chlorophyll a, chlorophyll b and carotenoids, and reflectance spectra parameters were not significantly different with that under control. However, when the sea salt concentration was 1.6%, the contents of chlorophyll a, chlorophyll b and carotenoids were decreased by 63.2%, 62.8%, and 47.2% (P < 0.01), respectively and reflectance spectra parameters red wavelength (λ_red) and red area (S_red) were significantly reduced (P < 0.05) compared with control. The red-edge normalized difference vegetation index (rNDVI), greenness normalized index (gNDVI), carotenoids reflectance indexes Ⅱ (CRI₇₀₀) and photochemical reflectance index (PRI) under 1.2% sea salt concentration was reduced by 27.3%、23.3%、19.5% and 43.9%, respectively compared with control. The rNDVI, modified red-edge normalized difference vegetation index (mND), gNDVI, modified red-edge ratio (mSR₇₀₀), carotenoids reflectance indexesⅠ (CRI₅₅₀),CRI₇₀₀ and PRI under 1.6% sea salt concentration was reduced by 42.4%, 43.9%, 32.6%, 21.5%, 47.2%, 49.9% and 58.5%, respectively compared with control. The maximum quantum yield of photosystemⅡ (F_v/F_m), quantum yield for electron transport (ΦE_o), electron transport flux per reaction center (ET_o/RC), density of reaction center (QA-reducing PSⅡ reaction centers) (RC/CS) and performance index on absorption basis (PI_ABS) under 1.6% sea salt concentration was reduced by 50.8%, 28.6%, 21.7%, 52.1%, and 92.3% respectively while the absorption flux per reaction center (ABS/RC) increased 96.9% compared with control. The above results showed that high salt stress inhibited the synthesis of the chlorophyll, reduced the absorption of the light energy, resulted in light inhibition and the damage of the acceptor side from PSⅡ, reaction center degradation or inactivation, and inhibited directly growth and development of bamboo. While under low salt stress, the salt tolerance of bamboo was improved by increasing chlorophyll content, light absorption, F_v/F_m, ΦE_o, ET_o/RC, RC/CS and PI_ABS.