Trigeneration is an energy-utilizing model of combination of cold, heat and power production. The evaluation methods of energy efficiency of trigeneration are investigated. The primary energy comparison models for both trigeneration and separate production are constructed and the features of energy saving conditions and energy saving rates are analyzed through simulations and calculations. The results show that there is large potential of energy saving space for trigeneration using absorption refrigeration unit, especially in the field of low temperature refrigeration.