The invention provides a preparation method for an isolated needle point with housing layers wrapped in dual manner, which relates to a scanning probe. The method comprises the following steps: 1) using a chemical etching method to prepare a needle point; 2) wrapping the surface of the needle point with a housing layer; and 3) using high polymer materials to package the part of the needle point wrapped by the housing layer in step 2 excluding the needle point end for a second time to obtain an isolated needle point with the housing layers wrapped in a dual manner. According to the invention, an atomic layer deposition technique is adopted and different source precursors are used so that the needle point surface can be wrapped by different inert housings. Through the control over the number of circulation turns of different source precursors, the thickness of the housing layer can be accurately controlled. The wrapping in dual manner can prevent the non-analyte molecules in the solution from interfering with the signal generated at the needle point and can isolate the interference of the Faraday current. Therefore, the method can be applied to electrochemical needle-enhanced Raman spectroscopy, electrochemical scanning tunneling microscope and electrochemical scanning microscope. Capable of being universally applied, the method can also be used to the wrapping of other needle points, like silver needle points, AFM needle points, and platinum iridium needle points. The method is simple to perform and is suitable for large batch production.