The invention discloses a tube connection device of a car double air conditioning system. The tube connection device of the car double air conditioning system comprises a liquid storing dryer, a front air conditioning box, a rear air conditioning box and a condenser, wherein the liquid storing dryer is connected to the condenser through a first wind pipe, the condenser is connected to the front air conditioning box and the rear air conditioning box through a first liquid pipe and a second liquid pipe, the front air conditioning box is connected to the liquid storing dryer through a second wind pipe, the rear air conditioning box is connected to the liquid storing dryer through a third wind pipe, a flange and the liquid storing dryer are integrated, and the second wind pipe, the third wind pipe, the first liquid pipe and the second liquid pipe are all connected to the liquid storing dryer through the flange. According to the tube connection device of the car double air conditioning system, by arranging the liquid storing dryer on the front end of the front air conditioning box and integrating the liquid storing dyer to a liquid storing drying bottle through the flange, integrated tube connection is achieved, and an overall length of the tube is obviously shortened compared with the prior art, pressure loss of the system is reduced, assembly performance of the system is improved, and a refrigerating effect is further improved.