The invention relates to a structural 
adhesive and particularly relates to a single-component shock-resistant low-
viscosity structural 
adhesive and a preparation method thereof, wherein the single-component shock-resistant low-
viscosity structural 
adhesive is suitable for bonding motors and other structures. The preparation method comprises the following steps of (1) mixing liquid 
epoxy resin (40-80 parts) and a 
toughening agent (7-15 parts), and stirring at the temperature of 15-30 DEG C for 1h; (2) adding a curing agent (9-13.5 parts) while stirring, and continuing to stir at the temperature of 15-30 DEG C for 1h until uniformly mixing; (3) adding an 
accelerant (7-8 parts) while stirring, and continuing to stir at the temperature of 15-30 DEG C for 0.5h until uniformly mixing; and (4) adding a 
coupling agent (0-0.5 part) and 
pigment (0-1 part), and stirring at the temperature of 15-30 DEG C for 1h until uniformly mixing. Compared with the prior art, the single-component shock-resistant low-
viscosity structural adhesive has the advantages that the 
toughening agent used by the invention is polyether amine, so that the high adhesive strength and 
temperature resistance of an 
epoxy system are remained, the viscosity of the 
system is reduced, and the flexibility and 
impact resistance of the adhesive are improved. The single-component shock-resistant low-viscosity structural adhesive is low in viscosity, and the adhesive can be coated on elements which are small in bonding gap and not easy to coat through self-
permeation, so that the work efficiency can be greatly increased. A synthesis reaction process is simple, easy to operate and low in cost, and a product is wide in application range.