The utility model relates to an inert gas and heat energy integral machine for cleaning a crude oil storage tank, relating to a device for cleaning the crude oil storage tank and simultaneously generating the inert gas and the heat energy. A steam tube (1) and a fume removing tube (2) are respectively fixed on the upper side of a boiler (12) of the utility model. A tail gas input tube (3) is connected between the inlet end of a dry-type heat exchanger (4) and the fume removing tube (2). The inlet end of a blower (7) and the outlet end of the dry-type heat exchanger (4) are connected with a tail gas output tube (5). The outlet end of the blower (7) is connected with the output tube (6) of the inert gas. An upper through tube (8) and a lower through tube (10) are respectively connected between the upper side of a mollification water box (9) and the lower end of the dry-type heat exchanger (4). The utility model has the advantages that the structure is reasonable, the security and efficiency of cleaning the tank are increased, the running cost of cleaning the tank is reduced, the time of cleaning the tank is shortened and the periods of cleaning the tank is guaranteed. The inert gas and heat energy integral machine for cleaning the crude oil storage tank generates the steam as well as the inert gas simultaneously. The heat required for cleaning the tank is solved and the problem of replacing the nitrogen is solved by making use of the tail gas for free.