The invention discloses an energy 
cascade comprehensive utilization method of LNG (
liquefied natural gas) cold energy. The energy 
cascade comprehensive utilization method comprises the following steps that firstly, the LNG cold energy of a deep cold part is converted into 
electric energy by 
Rankine cycle power generation; then, the LNG cold energy of a middle cold part is recovered by a 
cooling medium for supplying cold to a 
cold storage warehouse, meanwhile, the gasifying pressure of a power generation working medium in the 
Rankine cycle power 
generation process is controlled, the cold energy released by the gasifying of the liquid power generation working medium is matched with the temperature of the required cold energy of the 
cold storage warehouse, and the cold energy released by the gasifying of the liquid power generation working medium is used as a cold source for supplying cold to the 
cold storage warehouse; and the LNG cold energy of a shallow cold part is recovered and used as a cold source for an air conditioner 
system of a cold storage 
plant, and is used for supplying cold to 
product processing workshops of the cold storage, office buildings and storage warehouses. The energy 
cascade comprehensive utilization method has the advantages that through the 
system integration, the LNG is gradually used for power generation, cold supply of cold storage warehouses and cold supply of 
plant air conditioners from 
lower grade to upper grade according to the temperatures, the cascade utilization of the cold energy is realized, and the cold energy of the LNG is utilized highly efficiently in the low-temperature cold storages.