In order to determine the effect of deficit surge-root irrigation (SRI) in different phenological phases on mountain apples that are grown in Northern Shaanxi. Field experiments were conducted on the 6-year-old mountain apples. The effects of deficit SRI on photosynthetic characteristics, fruit yield, and quality of mountain apples in the area were then evaluated. With full irrigation (FI: 85–100%θf, where θfis the field capacity) as the control (CK), four levels of deficit irrigation were applied: light (DIL: 90%FI), moderate (DIM: 75%FI), severe (DIS: 60%FI), and extreme (DIE: 45%FI) deficit irrigation. They were applied during the spur leaves stage (stage I) and fruit expansion stage (stage III) of the apples. The results showed that the photosynthetic characteristics of apple leaves were stronger during stage III than stage I. In the same phenological stage, the photosynthetic capacity under DILwas discovered to be nonsignificantly different to under CK. Compared with CK, fruit yield and water use efficiency under III-DILand I-DILwere nonsignificantly increased, but others decreased. The technique for order of preference by similarity to the ideal solution (TOPSIS) method found that I-DILresulted in the highest comprehensive apple quality, followed by III-DIL, and III-DIEresulted in the lowest fruit quality. To summarize, the use of light deficit irrigation during the spur leaves stage (I-DIL) and fruit expansion stage (III-DIL) could stabilize fruit yield and improve apple quality. This study’s results provide a theoretical basis for further scientific research of SRI and the management of mountain apple tree irrigation in Northern Shaanxi, China.