A soldering component and a method of fitting it to boards are introduced. The soldering component includes a body and a fitting portion. The fitting portion is fitted to an object. The body has an engaging portion with an elastic retraction space conducive to elastic retraction of two or more engagement portions, allowing the engagement portions to engage with another object. The soldering component has a weldable surface to be soldered to a weldable surface of the object. The weldable surface of the object has a built-in solder layer adapted to be heated for soldering the soldering component and the weldable surface of the object together. The soldering component is disposed in a carrier, taken out with a tool, compared with the object by a comparison device to determine a fitting position on the object, positioned at the fitting position with the tool, thereby being fitted to the object.