A gold-graphene nanoassembly-based mucin-1 chirality signal ultrasensitive detection method, belonging to the technical field of material chemistry. The present invention comprises gold nanoparticle synthesis, graphene nanomaterial preparation, gold nanoparticle and mucin-1 aptamer coupling, graphene and mucin-1 aptamer partially complementary sequence coupling, gold-graphene nanostructure assembly, and TEM and chirality signal characterisation and determination. A relationship between the concentration of mucin-1 and a chirality signal of an assembly is established on the basis that different concentrations of mucin-1 relate to different dissociation degrees of the assembly and thus affect the strength of the chirality signal, and said relationship is used to implement the quantitative detection of mucin-1. The present invention provides a method for the ultrasensitive detection of a mucin-1 amount via a circular dichroism signal, and prepares a gold-graphene self-assembly nanostructure having high circular dichroism performance and good biological stability.