The present invention belongs to the field of biological detection. Multi-line immunochromatographic test strip for semi-quantitative detection of aflatoxin B1 comprises a paperboard, wherein a water-absorbing pad, a detection pad, a gold-labeled pad and a sample pad are adhered sequentially on one surface of the paperboard from top to bottom, wherein each adjacent pads is overlapped and connected, the detection pad uses a nitrocellulose film as a backing pad, the nitrocellulose film is provided with a transverse control line, a test line I, a test line II and a test line III, wherein the control line is coated with a rabbit anti-mouse polyclonal antibody, and the test line I, test line II and test line III are coated with aflatoxin B1-bovine serum albumin conjugate (AFB1-BSA), respectively: and the gold-labeled pad is transversely coated with a nanogold-labeled anti-aflatoxin B1 monoclonal antibody. Said test strip is used for semi-quantitative detection of aflatoxin B1, and is characterized by quick detection, simple procedure and high sensitivity.