The invention discloses a soaking dyeing method for cone yarns. The soaking dyeing method comprises the following steps: (1) yarn preparation and inspection; (2) threading; (3) adjustment of a bath ratio and calculation of the usage amounts of reagents; (4) preparation of a dye; 5) dyeing; (6) soaking and dehydrating; (7) washing with water; (8) soaping; and (9) washing with water again. Comparedwith the prior art, the invention has the following beneficial effects: the dyeing method is simple to operate and high in dyeing efficiency; the two procedures of liquid preparation and dyeing can becarried out simultaneously without mutual interference, so the efficiency of dyeing is improved; the usage amount of caustic soda in a bottoming solution is greater than a theoretical calculation value, so the hydrolysis of a sodium salt of azoic coupling component hydroxyl groups is prevented, and the influence of carbon dioxide and acid gas in the air is also prevented; and the existence of properly excess free base in the bottoming solution can protect the stability of the bottoming solution, so the stability of the dye can be ensured, and uniform dyeing of the yarns is benefited.