The invention provides an ultrathin double-sided adhesive tape. The ultrathin double-sided adhesive tape comprises a film protection layer, a first adhesive layer, a main film layer, a second adhesive layer and a peeling layer and the above layers orderly contacts. The first adhesive layer is prepared from a first main adhesive, a first solvent and a first curing agent through mixing. The second adhesive layer is prepared from a second main adhesive, a second solvent and a second curing agent through mixing. The first and second curing agents are isocyanates so that the ultrathin double-sided adhesive tape has high viscosity, no adhesive overflow after transection, good bonding effects and high transparency and can meet the existing requirements of the ultrathin double-sided adhesive tape.