The invention discloses a method that detects 
Staphylococcus aureus 
enterotoxin by a composite nano 
metal structure, which comprises the following steps: (1) a substrate is chosen and cleaned, and a 
polystyrene nano-sphere layer is self-assembled on the substrate; (2) the produced self-assembled 
polystyrene nano-sphere layer is taken as a die, and a 
silver film and a 
gold film are vapor-deposited on the self-assembled layer through a vapor deposition method; (3) the self-assembled 
polystyrene nano-sphere layer is removed through a Lift-off technique, and the nano 
metal array structure is obtained after array transformation; (4) the nano 
metal layer is activated by adopting a non-directional covalent connection method, and a biological 
molecular film layer that resists SE sheep 
monoclonal antibodies IgG is formed on the surface of the nano metal structure; (5) 
extinction spectrum of the nano metal structure is extracted by a 
spectrograph, and an 
extinction spectrum peak before the biological combination is obtained; (6) a solution to be detected is dropped on the 
substrate surface and blow-dried after the reaction, and step (5) is repeated; (7) the 
extinction spectrum peaks that are obtained before and after step (6) are contrasted, thus determining whether the solution to be detected contains SE. The method that detects the 
Staphylococcus aureus 
enterotoxin with the composite nano metal structure does not need the purifying and the marking of the solution to be detected, and can be applied into the quick detection of SE or other toxins in the same type.