The invention discloses a composition for detecting tumors. The composition participates in the immune turbidity reaction as an antibody carrier, can be used to detect various tumors and greatly improves the detection sensitivity. The composition for detecting the various tumors comprises various antibodies for recognizing a tumor specific antigen, a polymer and a colloidal gold solution; a preparation method of the composition is as follows: the various antibodies for recognizing the tumor specific antigen are respectively labelled by colloidal golds and form a copolymer with the polymer, the copolymer comprises the various antibodies labelled by the colloidal golds and used for recognizing the different tumor specific antigen, the copolymer then participates in the immune turbidity reaction as the antibody carrier and is used as an immunological enhancement in-vitro diagnostic reagent for detecting various tumors, various tumors are detected, and the composition is generally applicable, and the detection sensitivity is relatively high.