To investigate the effects of ridge ditch depth and fertilizing methods on nutrient utilization, yield and leaf quality of flue-cured tobacco transplanted under plastic film, a field experiment was conducted in 2025. Two ridge ditch (on ridge surface) depths (15 cm and 20 cm) and two fertilization methods (basal fertilizer applied in ridge ditch without soil covering and basal fertilizer applied in ridge ditch with soil covering) were established. The growth and development of tobacco, nitrogen (N), phosphorus (P), and potassium (K) nutrient absorption and utilization, as well as tobacco leaf yield and quality were analyzed. The results showed that: (1) The effects of ridge ditch depth on nutrient utilization and tobacco leaf yield and quality varied with soil covering methods. Under non-covering conditions, no significant differences were observed in N and K fertilizer use efficiency, tobacco leaf yield, or chemical quality among different ridge ditch depths (P > 0.05). Under covering conditions, compared with the ridge ditch depth of 15 cm, the 20 cm ridge ditch depth significantly decreased N, P, and K fertilizer use efficiency by 26.2%, 37.3%, and 33.0%, respectively (P < 0.05), significantly reduced total nitrogen content of cured middle leaves by 17.5% (P < 0.05), and significantly increased potassium and chlorine contents by 18.5% and 40.5%, respectively (P < 0.05). (2) The effects of soil covering on nutrient utilization of flue-cured tobacco also varied with ridge ditch depth. At the 15 cm ditch depth, compared with non-covering, soil covering significantly increased N, P, and K fertilizer use efficiency by 56.8%, 53.1%, and 44.4%, respectively (P < 0.05), significantly increased total nitrogen content of cured middle leaves by 18.1% (P < 0.05), and significantly decreased chlorine content by 29.4% (P < 0.05). At the 20 cm ditch depth, no significant differences were found in N, P, and K fertilizer use efficiency or cured tobacco leaf yield and quality between the two fertilization methods (P > 0.05). Among all treatments, the combination of 15 cm ditch depth with soil covering could maintain tobacco leaf yield while increasing nutrient accumulation and fertilizer utilization efficiency of flue-cured tobacco and improving leaf quality, representing a nutrient-efficient and simplified cultivation model recommended under the experimental conditions.