The invention provides a manufacturing method for a copper alloy porous liquid-absorbing core. The manufacturing method comprises the following steps of: a) preparing an electrolyte solution which isan aqueous solution comprising 0.5-1.8 mol/L of sulfuric acid and 0.1-0.5 mol/L of copper sulfate; b) cleaning the surface of a copper alloy substrate through a mixed solution of a surfactant and an alkali compound, activating by use of diluted hydrochloric acid, and cleaning completely; c) performing electro-deposition on the treated substrate in the electrolyte solution to form a porous structure on the substrate; and d) washing and drying a product obtained in step c), and sintering the product. Through the method, a porous structure with special arrangement and excellent capillary force and degree of permeability can be directly obtained on the surface of the substrate for being beneficial for working medium transmission.