Objectives A new Chinese oak silkworm variety with strong adaptability to adverse weather, tolerance to rough feed, stable and high yield was bred to ensure the stable and sustainable development of oak silkworm production in bivoltine areas including Inner Mongolia and other regions where one generation is bred a year. Methods Firstly, more than 10 varieties of oak silkworms participating in the experiment were screened with methods of stress and systematic breeding. Then, the heterosis was determined based on the elite agronomy traits and the ability to resist low temperatures and rainy weather. 4 varieties were selected and combined based on the determined results to breed a new quad- hybrid variety of oak silkworm called "Mengcan 114" ((Zhayi×Biyu183) × (Huang'an Dong× Qingliu)). Results The results of plot experiment and identification with rural production showed that the new variety was easy to reproduce and farm, and its elite agronomy traits were superior to that of the control variety 'Zhenzhu 1'. The cocoon mass of thousand grains, cocoon layer amount and cocoon production per kilogram egg was significantly increased by 14.00%, 14.28% and 19.46%, respectively, compared to the control variety. The length of ocoon filament and relaxation filament was significantly increased by 158.05 m and 171.89 m, respectively, compared to the control variety. The rate of relaxation and the silk extraction rate of fresh cocoons was 8.22% and 1.02% higher than that of the control variety, significantly increased by 18.56% and 15.36%. Conclusions "Mengcan 114" is robust and easy to farm, with high cocoon yield, concentrated cocoons, large cocoon shape, elite silk quality, and able to adapt to low temperature, high humidity and other stress. It is resistant to rough feeding, suitable for free range farming in bivoltine areas including Inner Mongolia and other regions where one generation is bred a year.