The equipment can provide low-temperature refrigerant from -25℃ to -45℃, which is suitable for places with various low-temperature cold source demands, such as the production process of medicine, chemical industry, metallurgy, electronics, foodstuffs and other industries, and can be used as the cold source host of large-scale cold storage and ice field. The product with heat recovery can provide hot water for domestic use of 40～60℃, which plays the role of energy saving.