Large-scale pigeon farming in China is gradually increasing. However, studies on the basic nutritional requirements of breeding pigeons during lactation, which greatly influence the productivity and economic benefits of pigeon breeding, remain scanty. The objective of this study was to determine the optimal dietary energy/protein ratio requirements for lactating pigeons in summer. A total of 576 pairs of Mimas breeding pigeons were randomly divided into 12 groups (n= 48 per treatment), and each pair bred 4 squabs. A two-way ANOVA design with different protein levels (15%, 16%, 17%, and 18%) for factor A and different energy levels (12.6 MJ/kg, 12.8 MJ/kg, and 13.0 MJ/kg) for factor B was used to design 12 groups of experimental diets for feeding. The experiment lasted for 28 d. We found that ME level had little effect on breeding pigeons, but the CP level and dietary energy/protein ratio significantly affected the reproductive and growth performance of the pigeons. The lowest total weight loss (P< 0.01), and the highest egg production (P< 0.01) were observed in group 11 (18% CP, 12.8 MJ/kg). It had no effect on egg quality. Both ME and CP levels significantly affected the growth performance, slaughter performance and meat quality of squabs, and there was a strong interaction between CP and ME. The fastest growth rate (P< 0.01) was observed in group 11 (18% CP, 12.8 MJ/kg). The best CP and ME combination for the eviscerated weight, pectoral muscle weight, organ weight, 45 min meat color (L⁎, a⁎, b⁎), pH, and muscle fiber characteristics were also group 11. Finally, the regression model revealed that the best dietary energy/protein ratio was 17.92 to 19.02 kcal/g for squabs and 16.72 kcal/g for the breeding pigeons. There was a strong interaction between energy and protein levels in breeding pigeons during the lactation period, and the best production performance was at 18% CP 12.8 MJ/kg. And this is recommended to be applied as the energy/protein ratio dietary requirement for breeding pigeons during lactation in the summer “2 + 4” pattern.