Cross-country skiing is one of the most important competitive events in the Winter Olympics, and it is also the earliest competitive sports event in China’s winter snow events. However, due to the influence of factors such as economic development, climatic conditions, and regional resources, cross-country skiing has developed slowly in China and is still in a relatively backward position compared with developed countries such as Europe and the United States. In this paper, the modeling and analysis of the attitude calculation system is proposed, and the attitude recognition technology is applied to the high-intensity resistance training system of cross-country skiing. Several training elements such as special endurance training goals, training content, training methods, and training monitoring are presented. It demonstrates the rationality and feasibility of the high-intensity resistance training system for excellent cross-country skiers in cross-country skiing and arranges the strengthening training of the upper and lower limbs and waist and abdominal muscles of the athletes in a targeted manner. For 6–9 times a week, each endurance training is about 1–4 hours or strength training is about 15–90 minutes. The fastest time for men is 31 minutes 29 seconds 21, which is 1 second 88 higher than that before training, and the average score has improved by 6 seconds 80; the women’s fastest time was 24 minutes 06 seconds 21, which was 4 seconds 22 higher than that before training, and the average score increased by 7 seconds 70.