The present invention provides an electroless nickel plating solution supplying high flexibility to a plated layer and having improved stability. The electroless nickel plating solution according to an embodiment of the present invention is an electroless nickel plating layer using an electroless nickel plating method. The electroless nickel plating solution comprises: a nickel metal salt providing a nickel ion for plating, and containing sulfamic acid nickel; a reducer reducing the nickel ion for plating; a complexing agent forming a complex together with the nickel ion for plating; and a cyan-based stabilizer providing stability of the electroless plating solution and preventing the generation of pits in a flexible nickel plated layer.