Cupressus chengiana is an important ecological restoration species in the dry valley. In order to study the adaptive strategy of C. chengiana to environment, photosynthetic physiological characteristics and water physiological characteristics of C. chengiana were measured in wet season (July) and dry season (November), respectively. The results showed that:(1) For water physiology, compared with wet season, peroxidase (POD), soluble sugar (SS) and proline (Pro) of C. chengiana increased significantly in dry season (P<0.05), but leaf mass per area (LMA), predawn leaf water potential (Ψ_pl) and midday leaf water potential (Ψ_ml) decreased significantly (P<0.05). (2) For photosynthetic physiology, compared with wet season, stomatal conductance (G_s), transpiration rate (T_r), light-saturated net photosynthetic rate (P_nmax), initial carboxylation efficiency (CE), photosynthetic capacity (A_max), CO₂ compensation point (Γ), photorespiration rate (R_p), the maximum carboxylation rate (V_cmax), the maximum electron transport rate (J_max), triose phosphates utilization rate (TPU), J_max/V_cmax, excitation capture efficiency (F_v'/F_m'), actual photochemical efficiency of PSII (Ф_PSII), photochemical fluorescence quenching (qP) and electron transport rate (ETR) of C. chengiana decreased significantly in dry season (P<0.05), but dark respiration rate (R_d), water use efficiency (WUE) and non-photochemical fluorescence quenching (NPQ) increased significantly (P<0.05). In conclusion, in order to adapt to drought, low temperature and other environmental stress in dry season, C. chengiana adopted the water use strategy by increasing soil moisture acquisition ability and reducing water loss, the increasing photosynthetic product consumption strategy, and the photosynthetic organ protection strategy by increasing heat dissipation.