The invention discloses a preparation method of a polyamide polyether organosilicone ternary polymerization type hydrophilic finishing agent, and belongs to the technical field of textile and chemical industry. The preparation method comprises the steps that hexamethylenediamine, adipic acid, double-end carboxyl polyethylene glycol and double-end amino polyether silicone oil are matched and mixed to be uniform according to the amount of substance, nitrogen protection is introduced in, the temperature is slowly increased for a reaction, phosphorous acid and a manganese dioxide solid body are added, and the temperature is increased for normal-pressure condensation polymerization; a sodium chloride solid body with the same mass as the phosphorous acid is added, slow stirring, cooling and standing layering are carried out, then, a water layer is removed, and the polyamide polyether organosilicone ternary polymerization type hydrophilic finishing agent is obtained. On the basis of the prior art, the reaction condition is optimized, and the manganese dioxide solid body is added as the catalyst for condensation polymerization, so that the reaction is carried out at normal pressure, and industrial production is facilitated; meanwhile, the prepared finishing agent has the good hydrophilic finishing effect on fabric, has the good improvement on the fabric soft hand feel, antistatic property and washing resistance, and is high in economic benefit.